POST SMTP Mailer – Email log, Delivery Failure Notifications and Best Mail SMTP for WordPress


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WordPress Mail SMTP Plugin

Post SMTP is a next-generation WP Mail SMTP plugin that assists and improves the email deliverability process of your WordPress website.

Easy-to-use and reliable – 300,000+ customers trust Post SMTP Mailer to send their daily WordPress emails to millions of users worldwide.

Post SMTP is not another WP Mail SMTP clone like WP Bank or Easy SMTP. It helps provide authentication that makes sure your emails get delivered and don’t end up in the spam filter or worse, the undelivered email queue.

What makes Post SMTP the best WP Mail SMTP plugin?

  • Post SMTP’s intelligent setup wizard helps guide you each and every step of the way from getting started to sending test emails.
  • The connectivity test scans your SMTP server to detect firewall blocks and eliminate configuration mistakes.
  • The built-in Email log is an invaluable resource for diagnosing problems with emails.
  • OAuth 2.0 increase the security and protection of email password by discouraging the idea of storing your email password in the WordPress database where it might be found.

Even hosts that block the standard SMTP ports, like GoDaddy or Bluehost, can’t stop your email as Post SMTP can deliver via HTTPS if it can’t use SMTP.

Post SMTP Features

  • Easy-to-use, powerful Setup Wizard for perfect configuration
  • Commercial-grade Connectivity Tester to diagnose server issues
  • Log and resend all emails; see the exact cause of failed emails
  • Supports International alphabets, HTML Mail and MultiPart/Alternative
  • Supports forced recipients (cc, bcc, to) and custom email headers
  • SASL Support: Plain/Login/CRAM-MD5/XOAUTH2 authentication
  • Security Support: SMTPS and STARTTLS (SSL/TLS)
  • Copy configuration to other instances of Post
  • Supports the proprietary OAuth 2.0 implementations of Gmail, Hotmail and Yahoo
  • Fire-and-forget delivery continues even if you change your password.
  • Set up an app password in your Google account.

  • πŸ‘‰ NEW: One-of-a-kind Mobile App for monitoring your WordPress emails on the go, you can view detailed email logs, check email errors, and resend them with a single tap directly from your mobile.

Post SMTP Mobile App – Get an instant pulse of your WordPress emails

πŸ‘‰ Keep track of Your Emails: You can monitor all the emails sent from your WordPress site and check the status of each email.

πŸ‘‰ Get Instant Alerts: When an email fails to deliver, you will receive an instant notification on your phone.

πŸ‘‰ Resend Failed Emails: With one tap on your app, you can resend any failed email.

πŸ‘‰ Preview Any Email: You can preview your emails and see how it looks.

πŸ‘‰ Manage Your Site: Check which WordPress sites are connected to your app and switch between them with ease [Coming soon].

πŸ‘‰ Troubleshoot Errors: Quickly fix any email failure issues by viewing the error details with a single tap.

Slack notifications

Receive Post SMTP notifications on your Slack app. If you approve “Post SMTP Notifications” app for Slack, you will be notified on any selected workplace about your failed emails.

Post SMTP Notification Chrome Extension

Post SMTP Notification Chrome Extension – Install Post SMTP’s official Chrome Extension to receive notifications of failed emails on your WordPress website.

Technical Documentation

You can read our Post SMTP technical documentation for more details including setting up the plugin and configuring other SMTP options. Also, stay up-to-date on new plugin updates, changes, modifications, and related news by subscribing to the Post SMTP blog.

Help & Support

You can contact our support team by filling out the form on our website. You can raise a request for Post SMTP Mailer Supports using our support portal.

Support for Pro Extension – You can submit a support request for Post SMTP Mailer Pro Extension by visiting our support portal

Configuration Request – Having trouble configuring Post SMTP Mailer for your WordPress website? Users who are having trouble setting up or configuring the plugin can fill out the configuration request form and connect with our support team.

What is SMTP and why do you need it?

Simple Mail Transfer Protocol or SMTP is the protocol used for sending emails over the internet. Your email client uses SMTP to send a message to a mail server, which then uses SMTP to relay the message to the correct receiving mail server.

In essence, SMTP is a set of commands that authenticates and directs the transfer of electronic mail. When configuring your email program, you will typically need to set the SMTP server to your local ISP’s SMTP settings.

Looking for Post SMTP Pro Extensions?

Post SMTP Pro Extensions are everything you need to enhance your WordPress email deliverability experience. Check our extensions for Amazon SES, Advanced Email Delivery and Logs, and Office365.

Office365 API delivery
Office365 Pro Extension allows you to connect PostSMTP with your Outlook and Microsoft 365 accounts to improve email deliverability.

Amazon SES API delivery
Amazon SES Pro Extension combines Amazon’s mail service provider with PostSMTP’s powerful and easy-to-use SMTP mailing features.

Report & Tracking Pro Extension
Report and Tracking Pro Extension gives you detailed reports and statistics of your website’s email performance. You can filter email statistics by day/week/month and track who viewed your emails. You can also view your email’s open rate. Also, the addon sends you daily, weekly or monthly email reports directly in your inbox to make sure you are aware of your email performance.

Zoho Mail API delivery
Zoho Mail Pro Extension gives you the power to connect PostSMTP with your Zoho Mail account to improve email deliverability of your WordPress site.

Twilio Pro Extension
Twilio Extension allows you to add your phone number so that you can receive SMS notifications and alerts when emails are not delivered to your recipients.

Mail Control Pro Extension
Mail Control Pro Extension allows you to control Post SMTP’s email actions like sending email alerts to authors, webmasters, and new users.

Advanced Email Delivery and Logs Extension
With the Advanced Email Delivery and Logs Extension, boost your email efficiency and improve deliverability. Also, implement effective email quota management and streamlined log storage for optimal email communication.


Post SMTP PRO Bundle offer access to all pro extensions along with other benefits including 1-year extension updates and support, Email Reporting, Logging, and Tracking, all other SMTP Services and a 30-day money-back guarantee.

API (HTTPS) Email Support for different SMTPs

  • Gmail API for sending Gmail and Google Apps email (requires a Google account)
    Often bloggers and small business owners don’t want to use third-party SMTP services. Well you can use your Gmail or G Suite account for SMTP emails.

  • Mandrill API for sending any email (requires a Mandrill account)
    Mandrill is an email infrastructure service offered as an add-on for MailChimp that you can use to send personalized, one-to-one e-commerce emails, or automated transactional emails.

  • Mailgun API for sending any email (requires a Mailgun account)
    Mailgun SMTP is a popular SMTP service provider that allows you to send large quantities of emails. They allow you to send your first 10,000 emails for free every month.

  • SendGrid API for sending any email (requires a SendGrid account and PHP 5.3)
    SendGrid has a free SMTP plan that you can use to send up to 100 emails per day. With our native SendGrid SMTP integration, you can easily and securely set up SendGrid SMTP on your WordPress site.

  • Sendinblue API for sending any email (requires a Sendinblue account and PHP 5.3)
    SendinBlue is an effective and great email software for Small to Medium businesses. You can build customer relationships with an all-in-one digital marketing toolbox. Their free plan allows you to send up to 300 emails per day.

  • PostMark API for sending any email (requires a PostMark account and PHP 5.3)
    Postmark is a cloud-based email management software designed to help businesses handle and streamline the delivery of emails.

  • SparkPost API for sending any email (requires a SparkPost account and PHP 5.3)
    SparkPost is a cloud-based email analytics solution designed to help businesses of all sizes optimize email performance, deliverability, engagement, and more.

  • Mailjet API for sending any email (requires a Mailjet account)

Compatibility & Support


  • WordPress 5.6 and PHP 5.6 with SPL and iconv
  • Memory: 750KiB per process at idle
  • Reliable mail delivery with custom email domains requires an SPF record
  • Reliable SMTP delivery requires credentials with an email service provider

Grant OAuth permission error messages

Please note that the Client ID and Client Secret fields are NOT for your username and password. They are for OAuth Credentials only.

Error authenticating with this Client ID. [Error executing wp_remote_post: The user has blocked requests via HTTP.]

Your WordPress site is configured with WP_HTTP_BLOCK_EXTERNAL to prevent outbound connections. Add a whitelist rule to wp-config.php:

define(‘WP_ACCESSIBLE_HOSTS’, ‘,,’);

Error authenticating with this Client ID. [Error executing wp_remote_post: Failed to connect to xxxx]

There is a firewall on port 443 between you and the OAuth2 server. Open up the port for outbound connections.

Error: redirect_uri_mismatch

  • You did not enter the Redirect URI correctly.
  • You used an IP address instead of a domain name (not allowed)

SMTP Error Messages

Communication Error 334 make sure the Envelope From Email is the same account used to create the Client ID.

  • This is almost always caused by being logged in to Google/Microsoft/Yahoo with a different user than the one Post is configured to send mail with. Logout and try again with the correct user
  • Login to Webmail and see if there is an “Unusual Activity” warning waiting for your attention

Could not open socket

  • Your host may have installed a firewall between you and the server. Ask them to open the ports.
  • Your may have tried to (incorrectly) use SSL over port 587. Check your encryption and port settings.

Operation Timed out

  • Your host may have poor connectivity to the mail server. Try doubling the Read Timeout.
  • Your host may have installed a firewall (DROP packets) between you and the server. Ask them to open the ports.
  • Your may have tried to (incorrectly) use TLS over port 465. Check your encryption and port settings.

Connection refused

Your host has likely installed a firewall (REJECT packets) between you and the server. Ask them to open the ports.

503 Bad sequence of commands

You configured TLS security when you should have selected no security.

XOAUTH2 authentication mechanism not supported

You may be on a Virtual Private Server that is playing havoc with your communications. Jump ship.

Mail ends up in the Spam folder

To avoid being flagged as spam, you need to prove your email isn’t forged. On a custom domain, its up to YOU to set that up:

  • Ensure you are using the correct SMTP server with authentication – the correct SMTP server is the one defined by your email service’s SPF record
  • If you use a custom domain name for email, add an SPF record to your DNS zone file. The SPF is specific to your email provider.
  • If you use a custom domain name for email, add a DKIM record to your DNS zone file and upload your Domain Key (a digital signature).


  • WordPress Dashboard showing both the Post widget and At a Glance widget
  • Main Settings screen - shows Main Menu and current status (new installation)
  • Setup Wizard (step 1) - Import data from other plugins
  • Setup Wizard (step 4) - Connectivity Test
  • Manual Configuration - Account Settings: Password Authentication
  • Manual Configuration - Account Settings: OAuth 2.0 Authentication
  • Manual Configuration - Message Settings
  • Manual Configuration - Advanced Settings
  • Test Email utility screen - Oops! Wrong password
  • Emai Log screen
  • Connectivity Test utility screen
  • Diagnostic Information screen


To send email reliably, you must use the SMTP server assigned to that email. If Post is unable to connect to the right SMTP server, you may have to ask your host to open the ports, or create a new email account managed by your host, or switch hosts!
The Connectivity Test utility will tell you which ports are open and the actions available to you.

Easy to install and setup! (Recommended for all users)

  1. Install and activate the plugin through the ‘Plugins’ menu in WordPress.
  2. In the WordPress ‘Settings’ menu select ‘Post SMTP’.
  3. Choose ‘Start the Wizard’ and follow the instructions.

To manually configure Password Authentication (Intermediate users only)

  1. Choose configure manually
  2. In ‘Transport’, choose ‘SMTP’
  3. In ‘Outgoing Mail Server Hostname’, enter the SMTP Server’s hostname
  4. In ‘Outgoing Mail Server Port’, enter the SMTP Server’s port
  5. In ‘Security’ choose the appropriate type (a good guess is SMTPS for port 465, STARTTLS otherwise)
  6. In ‘Authentication’, choose the authentication type (a good guess is ‘Plain’)
  7. If your Authentication method is not ‘None’, enter your username (probably your email address) and password.
  8. Choose the ‘Message’ tab.
  9. In ‘Envelope From Address’ enter your email address. This MUST be the same address you login to webmail with.
  10. In ‘Message From Address’ enter your email address. Or this can be an alias, mailing list, or group email if you wish.
  11. Choose the Save Changes button.
  12. Send yourself a test email.

To manually configure OAuth 2.0 Authentication (Advanced users only)

  1. Choose configure manually
  2. In ‘Transport’, choose ‘SMTP’
  3. In ‘Outgoing Mail Server Hostname’, enter the SMTP Server’s hostname
  4. In ‘Outgoing Mail Server Port’, enter the SMTP Server’s port
  5. In ‘Security’ choose the appropriate type (a good guess is SMTPS for port 465, StartTLS otherwise)
  6. In ‘Authentication’ choose ‘OAuth 2.0’
  7. Post will give you a link to the Client ID maintenance page of your email service provider. Create a Client ID for your WordPress site.. instructions for this are detailed in the FAQ
  8. Copy your generated Client ID and Client secret into the plugin’s Settings page.
  9. Choose the ‘Message’ tab.
  10. In ‘Envelope From Address’ enter your email address. This MUST be the same address you login to webmail with.
  11. In ‘Message From Address’ enter your email address. Or this can be an alias, mailing list, or group email if you wish.
  12. Choose the Save Changes button.
  13. Choose the ‘Request OAuth2 Permission’ link and follow the instructions.
  14. Send yourself a test email.


What is OAuth 2.0?

A modern replacement for traditional password-based authentication. Post supports the OAuth 2.0 implementations of all three major e-mail providers: Gmail, Hotmail and Yahoo Mail.

How does OAuth 2.0 work?

Post requests a limited access OAuth 2.0 token (valet key) to access the APIs (enter the house) and perform a specific service (handle Gmail, stay out of Google Docs) with no need for you to surrender your username and password credentials (master house key).

Once access is granted, Post commandeers the WordPress wp_mail() function to provide an incredibly stable mail sub-system.

There are many reasons why OAuth 2.0 is better than any password-based mechanism:

  • Post will never ask for your password, so your password can’t be stolen
  • If you change your password regularly, you will never have to update Post’s configuration
  • You have tighter control over the data Post has access to. For Google users it can never access your Calendar or Docs or YouTube; for Yahoo users it can never access your Flickr
  • If your WordPress site gets hacked, you can revoke Post’s email access without impacting any other application or website that has access to your account

NEVER give out your Gmail, Microsoft or Yahoo password to a 3rd-party or 3rd-party program that you don’t fully trust.

What is a Client ID?

To use OAuth, your website needs it’s own Client ID. The Client ID is used to control authentication and authorization and is tied to the specific URL of your website. If you manage several websites, you will need a different Client ID for each one.

How do I get a Microsoft Client ID? (For Hotmail/Live/ users only!)

  1. Go to Microsoft account Developer Center and select ‘Create application’.
  2. In the ‘Application name’ field enter ‘Post SMTP’. Select ‘I accept.’
  3. Select ‘API Settings’ from under ‘Settings’.
  4. In ‘Redirect URL’, enter the redirect URI given by Post (either from the wizard, or from the manual configuration page). Select Save.
  5. Select ‘App Settings’ from under ‘Settings’.
  6. Enter the Client ID and Client Secret displayed here into Post’s settings page.

How do I get a Yahoo Client ID? (For Yahoo Mail users only!)

  1. Go to Yahoo Developer Network and select ‘Create an App’.
  2. In the ‘Application Name’ field enter ‘Post SMTP’. For ‘Application Type’ choose ‘Web Application’.
  3. In ‘Home Page URL’, enter the ‘Home Page URL’ given by Post.
  4. In ‘Callback Domain’, enter the ‘Callback Domain’ given by Post.
  5. Under ‘API Permissions’ choose ‘Mail’. Under ‘Mail’ choose ‘Read/Write’
  6. Click ‘Create App’
  7. Enter the Client ID and Client Secret displayed here into Post’s settings page.

How can I revoke Post’s OAuth 2.0 access?

How can I report security bugs?

You can report security bugs through the Patchstack Vulnerability Disclosure Program. The Patchstack team help validate, triage and handle any security vulnerabilities. Report a security vulnerability.


25 Novembre 2023
Amazingly easy to configure, even I only needed 2 minutes and in the end it worked.
22 Novembre 2023
Got the Microsoft 365 extension. Had trouble configuring the plugin. The team was super helpful, extremely responsive and fixed the problem in less then 24h. Highly recommended!
9 Novembre 2023
I lost a full day and a half trying to install this plug in on my own. Finally bought the $40 basic installation help, Muhammad Haseeb was super helpful and patient even though it was 1 am his time. Turns out my office365 email was super cranky but Muhammad was able to set up a gmail email and it's working fine. I should have saved myself the day and a half and called these guys to begin with! thanks Muhammad, much appreciated!
9 Novembre 2023
While this plugin was able to let me send email from my website where others failed, the instructions for setting up a Google API were out of date, which meant I struggled to get it working. Once working, it seems very reliable. I realise Google are always changing things, and it can't be easy to keep everything updated. I am grateful to the developers for providing this plugin. The logs are also invaluable for checking that everything is working.
8 Novembre 2023 1 risposta
Hi, thanks for your great code. I just want to point out that the English strings in your error messaging are incorrect. You getting this message because an error detected while delivered your email. should be You are getting this message because an error was detected while delivering your email.
Leggi tutte le recensioni di 410

Contributi e sviluppo

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Changelog (registro delle modifiche)

2.8.5 – 2023-11-23

  • Fix: In some cases, there was an issue disconnecting mobile application.

2.8.4 – 2023-11-20

  • Fix: From name and emails, prevention settings were not being saved correctly in some cases in the new wizard.
  • Fix: In some sockets, the API keys getting saved were encoded in multiple layers.

2.8.3 – 2023-11-17

  • Fix – Getting error when saving settings in some scenarios.
  • Improvement – Optimized QR code scanning module for Post SMTP mobile app to avoid any scanning delays

2.8.2 – 2023-11-14

  • Improvement – PHP < 7.3 compatibility added.

2.8.1 – 2023-11-13

  • Fix – Other SMTP option in the wizard was not saving the settings correctly.

2.8.0 – 2023-11-13

  • NEW – Introducing a NEW 3-step wizard to speed up the initial setup.
  • NEW – Added documentation within the wizard to ease out the setup
  • NEW – Added new socket/email service for Mailjet
  • NEW – Added support for default socket within wizard (you can use this option in case you want to use the logs functionality only)
  • Fix – Updated the error string as reported by @interaptivre

2.7.2 – 2023-11-01

  • Improvement – Mobile App banner improvement.

2.7.1 – 2023-11-01

  • NEW – Show Mobile App Notice on Post SMTP dashboard
  • Improvement – Improved SQL query to meet latest security standards
  • Improvement – Added patch to avoid script execution in log content.

2.7.0 – 2023-10-26

  • NEW – Added support for POST SMTP app. Visit documentation for more information
  • Fix – Raw HTML was sent when using ElasticEmail service.
  • Fix – Raw HTML was sent when resending emails from the log section.

2.6.2 – 2023-10-19

  • Tested up to WordPress v6.3.2

2.6.1 – 2023-10-03

  • Fix: Removed broken link from test email.
  • Improvement: Improved SQL query to meet latest security standards.
  • Improvement: Replaced sanitize_text_field() with intval() as suggested by WP Scan team.

2.6.0 – 2023-09-12


  • Elastic mail socket added
  • When resetting the plugin settings, the user can check to preserve logs from getting removed
  • MainWP integration added. How-to instructions will be available publicly soon.


  • When using PHPMailer, the failed email log was not creating


  • Now, users can skip the banner from the dashboard. – 2023-08-29

  • API endpoint “SendinBlue” has been updated to “Brevo” – 2023-08-17

  • Minor Tweaks – 2023-08-16

  • Compatible & Tested up to WordPress v6.3


  • Added option to refresh recent logs in the dashboard without loading the page.
  • Added new hooks in the code to make the functionality extendable.

2.5.9 – 2023-07-18


  • Improved email log popup content


  • Reverted support for HTML view in email content popup with proper checks to avoid CSS conflicts.


  • Added new filter post_smtp_before_view_log to extend log section view.

2.5.8 – 2023-07-11


  • Added function to escape backend email content popup HTML.
  • Added Failed/success labels for better visibility.
  • Displayed error message on hover and in the popup to simplify the interface and UX in the log section.
  • Updated Feedback SDK to the latest version


  • Fix: Pagination was getting reset on resending emails.

2.5.7 – 2023-06-21


  • Enhance code quality and strengthen security measures.

2.5.6 – 2023-06-08


  • Critical error was being thrown when reseting the plugin.

2.5.5 – 2023-05-29


  • Some of logs were overriding log page CSS.


  • Added title on log status for better user experience.
  • Translation string improvement.

2.5.4 – 2023-05-24


  • Logs were not created in some cases.

2.5.3 2023-05-16


  • Fixed E_WARNING appearing on activation in some cases.

2.5.2 – 2023-05-12


  • Fixed the issue where users were getting stuck in the initial migration stage.


  • On completing the migration process, limit the notice to the logs section only to delete old logs.
  • Added an option to disable migration notifications for seven days on clicking the cross icon on notice.
  • Added a new feature that allows users to revert a migration. This way, they can retry the migration process or switch back to the old logs interface if required.
  • Added an option to skip the migration process for those who do not wish to transfer their old logs and want to switch to the new interface.
  • Added permission check before creating/writing error log during migration.

2.5.1 – 2023-05-10


  • Added a link to learn more about migration.
  • Added a condition to initiate the migration and logging only if the new custom table exists.


  • Improved database migration process to handle potential failures.

2.5.0 – 2023-05-09


  • Introducing a new log section that is both lightweight and optimized, capable of accommodating millions of entries.
  • Added a migration wizard to help move existing logs to new custom tables from the old version.

2.4.9 – 2023-04-27


  • Uncaught Error: Cannot use object of type WP_Error as array
  • Fixed deprecation notice for PHP Version > 8.0


  • Added condition for notice on how to fix broken emails

2.4.8 – 2023-04-17

Bug Fix

  • Fixed deprecated functions on Php 8.x

2.4.7 – 2023-04-10


  • Updated feedback SDK to latest version
  • Added PHP 8.1 compatibility

2.4.6 – 2023-03-27

Bug Fixes

  • Added new option in the settings to fix broken emails.

2.4.5 – 2023-03-14

Bug Fixes

  • Reverted the fix to support minor PHP versions, impacting some other PHP versions.
  • NEW Filter post_smtp_incompatible_php added to fix the compatibility of minor PHP versions.

2.4.4 – 2023-03-08

Bug Fixes

  • Resolved an issue where warnings were generated due to an array to string conversion.
  • Fixed a problem where CC and BCC recipients were not properly added when using SendInBlue.
  • Addressed an issue where multiple recipients using SendInBlue were receiving emails individually instead of as a group.
  • Fixed an email formatting issue that occurred in certain PHP versions.
  • Corrected an issue where the friendly name feature was not functioning properly with SendInBlue.

2.4.3 – 2023-02-27

Bug Fixes

  • Fix – Code 400 error appearing in some cases for SendGrid with cc headers

2.4.2 – 2023-02-24

Bug Fixes

  • Email header request issue fixed for MailGun
  • Email attachment issue is fixed in SendGrid

2.4.1 – 2023-02-22

Bug Fixes

  • Fixed parse error on Php 7.2

2.4 – 2023-02-21


  • Replaced Mandrill SDK with Endpoints
  • Replaced SendGrid SDK with Endpoints

2.3.2 – 2023-01-06

Bug Fixes

  • Fixed error related to Reply-To appearing in some cases.

2.3.1 – 2023-01-05

Bug Fixes

  • Fixed issues appearing in PostmanLogFields.php
  • Emails were getting broken in some cases

2.3 – 2023-01-03

Bug Fixes

  • PHP errors appear in ajax requests in some cases.
  • Fixed comma breaking the From name in the log section
  • Reply-to Header not being added in some instances (Reported by @pierrehooker)


  • Updated sender header as per RFC-2822
  • Added PHP 8 Compatibility
  • Updated Google API SDK
  • Replaced MailGun SDK with endpoints
  • Replaced SendInBlue SDK with Endpoints

2.2.3 – 2022-12-27


  • Bug Fix – Support menu was disappearing in some cases

2.2.2 – 2022-12-19


  • SendGrid was missing on wizard
  • PHP Warnings

2.2.1 – 2022-12-13


  • Email template HTML was broken

2.2 – 2022-12-08

  • NEW
  • Added New Socket/ Email Service Postmark
  • Added New Socket/ Email Service SparkPost
  • SSRF Prevention
  • SQL Warning Removed
  • MailGun SDK Updated to Latest Version
  • Compatibility with BackupBuddy added
  • Multisite Plugin Update
  • Additional Headers were not saved properly in some cases
  • Import Button was not working in some cases

2.1.10 – 2022-10-10

  • Avoid redirection to wizard on activation
  • Issue in resend emails
  • Made backend setting fields visible
  • Email host message
  • Sendgrid message id to prevent spam emails

2.1.9 – 2022-09-9

  • FIX
  • User Compatibility Fix
  • Unauthorized error on wizard

2.1.8 – 2022-09-5

  • FIX
  • Php warnings

2.1.7 – 2022-08-30

  • FIX
  • Server side request forgery

2.1.6 – 2022-08-29

  • FIX
  • Server side request forgery

2.1.5 – 2022-08-25

  • FIX
  • Updated email header to prevent email from being SPAM

2.1.4 – 2022-08-18

  • NEW
  • Redirect the user to the setup wizard on activating the Plugin
  • Added action hook, “post_smtp_before_reset_plugin” to add an event before resetting plugin
  • Added action hook, “post_smtp_after_reset_plugin” to add an event after resetting plugin
  • Added notice to Grant Access after getting done with the wizard step to improve the UX


  • Tweaks for PHP Version 8+ compatibility
  • Freemius Language FIX
  • Security Fix to avoid XSS from admin settings
  • Mailster support updated for the latest version (thanks to @evrpress)
  • Typo fix: defualt to default (thanks to @jsilvermist)
  • Updated email header to prevent email from being SPAM

2.1.3- 2022-07-1

  • FIX
  • PHP Version Compatibility.

2.1.2- 2022-06-30

  • NEW
  • Integrated SDK for Feedback and support.
  • Added “Start wizard” button in setup notification to optimize UX for the end-user.

  • Improved
    Removed unused code

  • FIX
    Less secure App Banner appearing in non-appropriate cases – 2022-06-15

  • FIX
  • Sendinblue email header

2.1.1 – 2022-06-09

  • FIX
  • PHP Version Compatibility.

2.1 – 2022-06-09

  • NEW
  • All New UI
  • Sendinblue API Integration

2.0.27 – 2022-05-19

Add notice about Google Less Secure App.

2.0.26 – 2022-04-22

  • Bug Fixes
  • Email header was broken in some cases.

  • Improvements

  • Minor UI improvement.
  • llc Hostname added in ZendMail.

2.0.25 – 2022-04-06

  • Bug Fixes
  • WP 5.9 Compatibility Ballon UI issue.
  • Uncaught Error: Class PostmanAdminController not found.
  • Ajax error appearing due to Google API depreciated function.

  • Improvements

  • Code Optimization.
  • MIME version added to test mails to prevent emails from spam.
  • NEW Filter postman_test_email_args added to modify test email arguments.
  • NEW Action wp_mail_succeeded added to exectue on every success email delivery.

= 2.0.24 – 2022-02-13
* Update: THE FUTURE OF Post SMTP –

= 2.0.23 – 2021-04-22
* Fixed: WP_Scripts::localize called incorrectly message.

= 2.0.22 – 2021-02-14
* Update: Chrome extension URL change
* Fixed: Double save when extension save to option

= 2.0.21 – 2021-02-11
* Fixed: Security issue – nonce validation.
* Fixed: Class PostmanViewController not found
* New: New wp-config.php constant to disable the email logger = POST_SMTP_CORE_MAIL_LOG.

= 2.0.20 – 2021-01-19
* Fixed: All reported office 365 issues.
* New: Add link to Amazon SES Extension

= 2.0.19 – 2021-01-19
* Fixed: All reported office 365 issues.
* New: Add link to Amazon SES Extension

= 2.0.18 – 2021-01-17
* New: Plugin Extensions

= 2.0.16 – 2020-12-13
* Update: General Info

= 2.0.15 – 2020-08-12
* Fixed: WordPress 5.5 compatibility (stable)

= 2.0.14 – 2020-08-11
* Removed: WordPress 5.5 compatibility (bug)

= 2.0.13 – 2020-08-11
* Fixed: WordPress 5.5 compatibility
* Fixed: Email log filtering
* Fixed: Pushover notifications
* New: Suggest solution for email delivery errors

= 2.0.12 – 2020-05-18
* Updated: Readme file info

= 2.0.11 – 2020-02-25
* Fixed: Slack notifications

= 2.0.10 – 2020-01-21
* Fixed: HTML content type
* Fixed: Sendgrid crash when has duplicates recipients (bypass, Sendgrid issue).
* Fixed: Few OAuth undefined notifications
* Fixed: Duplicate Emails – When you have notify and confirm (Ninja forms, etc..)
* Fixed: Logs wp_error convert

= 2.0.9 – 2020-01-13
* Fixed: Notify on error bug – crash site
* Fixed: From header

= 2.0.8 – 2020-01-12
* Updated: Reply-To header bug

= 2.0.7 – 2020-01-12
* Updated: Improve PHPMailer method.
* Updated: Bug fixes.

= 2.0.6 – 2019-10-08
* Updated: Bug fixes.

= 2.0.5 – 2019-09-26
* New: You can now export logs to CSV.
* Updated: Few notifications errors, and minor improvements.

= 2.0.4 – 2019-08-27
* Updated: More security.

= 2.0.3 – 2019-08-21
* Fixed: A few security issues.

= 2.0.2 – 2019-05-19
* Fixed: Sendgrid code fix.
* Fixed: Default method (nothing configured) will use the default mail on the server and not SMTP.

= 2.0.1 – 2019-05-15
* New: Mailer Type – Added an option to send without overwrite the ‘wp_mail’ function, better compability to WordPress delivery. hopefully will be the default in the future.
* Updated: Sendgrid API was upgraded and rewritten to the new version.
* Fixed: Message-Id header was missing on SMTP
* Fixed: Email logger optimization – better query for large amount of records.
* Fixed: The localization was fixed to match translation system ( Thanks to Niels de Blaauw from Level-Level ).
* Fixed: Code and optimization ( Thanks to Niels de Blaauw from Level-Level ).

= 1.9.8 – 2019-02-18
* New: a new from field to the fallback – Can’t trust the username as “from” value (email address).

= 1.9.7 – 2019-02-17
* New: Fallback Feature – Configure a backup SMTP when emails are failing.
* New: WordPress Multisite compability – with global settings.
* New: Email Log capability – give other user cheking the logs.
* Fixed: compatibility with mailster plugin
* Fixed: Mandrill exception bug – Thanks to Niels de Blaauw from Level-Level

= 1.9.6 – 2019-01-29
* Added support for our new chrome notification extension.
* few fixes

= 1.9.5 – 2018-10-02
* Added support for Mailgun Europe region.
* Replace “buggy” mime_content_type php function

= 1.9.4 – 2018-08-03
The most stupid idea ever remove (auto security select)

= 1.9.3 – 2018-07-26
Removed auto configure for port 25 (can be TLS)

= 1.9.2 – 2018-07-23
Removed deprecated functions from 7.2 + comment unready feature

= 1.9.1 – 2018-07-22
Syntx stupid mistake

= 1.9.0 – 2018-07-22
* Better support for secure delivery
* Support for constants auth (inside wp-config), check the detailes our Blog
* Automatic encryption select base on the port input – 25, 465, 587, 2525

= 1.8.9 – 2018-04-24
* Sendgrid bug

= 1.8.8 – 2018-04-24
* file added to svn – contactform7

= 1.8.6 – 2018-04-24
* Fix lockfile erros
* Contact form 7 integration
* PHP 5.6 requirement

= 1.8.5 – 2018-04-19
* Remove Beta Woocommerce integration
* Better check for WPML less then version 3.9

= 1.8.4 – 2018-04-18
* New: Multiple notification options to failed emails
* Upgrade: The Gmail code was upgraded and code change to support large attachments
* Add: Fix release lock file error
* Change: “Not configured…” message is now dismissible

= 1.8.3 – 2018-03-21
* Fix: SendGrid API Call Structure (The previous try didn’t work)

= 1.8.2 – 2018-03-21
* Fix: SendGrid API Call Structure

= 1.8.1 – 2018-03-20
* New: Sendgrid API & Client Version 6
* New: Add email log ‘send to’ column
* Fix: fallback emails on hosting require the ‘-f’ parameter
* Fix: Using hostname insted of an IP
* Fix: Remove mailgun test folder ( virustotal issue )
* Fix: Additional bugs collected from support tickets.
* Added: added filters to from_name and from_email filters (local connection)
* change hostname extrect logic

= 1.8 – 2017-12-24
* New: Mailgun API integration
* New: New filter controls
* New: WPML conflict fix
* Fix: Minor old bugs

1.7.10 – 2017-11-21

* Fixed: bug while detecting transcript error

= 1.7.9 – 2017-11-20
* Fixed: misspled false
* Fixed: feedback form
* Fixed: Some localization strings
* Removed: deprecated function
* New: Option to input emails when resend email
* Added: explain message on email log filter

= 1.7.8 – 2017-11-17
* = Menu Items grouping =
* Fixed: IP detection error in some web hosts
* Fixed: Link open in new page attribute = _blank
* Fixed: Replace deprecated PHP 7 functions.
* Updated: Validator TLD’s list
* Added: Email log date and search filter.
* Added: Alert on sending error (Fallback to local mail)
* Added: Email body preview (not raw)

= 1.7.7 – 2017-10-17
* Fixed: Error sending files with sendgrid
* Fixed: Wrong attachments format in Mandrill
* Fixed: Wrong Sender Header in Mandrill

= 1.7.6 – 2017-10-17
* Missing sendgrid files
* Fixed: Localization slug

1.7.5 – 2017-10-07

  • Fixed: security issue (XSS)
  • Fixed: Small bug with Google API

1.7.2 – 2015-11-08

  • [Ticket] – v1.7 ignores the content-type header set in the Additional Headers. Fixed.
  • [Ticket] – Fixed an issue where v1.7 admin screens crash for non-admin users when Post is not configured. Fixed a multiste issue where v1.7 site admins lose access to their Post settings screen. Special thank-you to Domi2015 for giving me access for testing! πŸ™‚
  • Localized jQuery Validation messages
  • Localized MyMail messages
  • Put the local translation files back, as WordPress on-line translations do not work as advertised

1.7.1 – 2015-11-05

  • [Ticket] – the Optimizepress plugin calls wp_mail before the WordPress init hook, before Post is fully initialized, so I made a change to accomodate this behavior
  • [Ticket] – v1.7 admin screen may become inaccessible after upgrading. Fixed.
  • [Ticket] – v1.7 breaks compatibility with WordPress Leads. Fixed.

1.7.0 “Iliana” – 2015-11-03

  • Happy Halowe’en! 30,000 installations! – 2015-10-31
  • Integrated Mandrill API
  • Integrated SendGrid API
  • Language files have been removed from the plugin as translations are now performed on-line. If you are a non-English speaker please constribute!
  • Post commandeers email when activated and sends using the WordPress default of localhost:25 – this is for people who want to use it to diagnose email problems without configuring SMTP
  • Re-send failed e-mails from the Email Log screen
  • Added an internal ‘manage_Post_smtp’ capability for advanced management with, for example, User Role Editor
  • [Ticket][Ticket] Added an import/export tab to the Advanced Configuration screen for those who want to duplicate settings between sites.
  • [Ticket] Added option to disable e-mail address validation
  • [Ticket] Fix for fatal error when using a non-administrator in the admin menu.

1.6.24 – 2015-09-10

  • 20,000 installations! – 2015-09-09
  • Translated into Greek, thank-you Michael Kotsarinis!
  • Diagnostic Test displays all the wp_mail-related hooks of active plugins and themes
  • When validating e-mail addresses, Post will disclose which field has a validation issue in the error message
  • Default log entries bumped from 10 to 250
  • [Ticket] Added nasty fake input field hack to prevent browsers from autofilling username/password fields.
  • [Ticket] Added a warning to the Email Log for emails that have an empty subject line
  • [Ticket] Test Email detects Ajax errors and displays them in the Status window
  • [Ticket] Removed the references to images in Post’s copy of jquery-ui.css causing HTTP 404
  • [Ticket] Fixed an Ajax name collision with the plugin MemberPress
  • [Ticket] Some sites can not handle International (UTF-8) characters in the Test Email. Fixed.
  • [Ticket] Fix for PHP Notice: Undefined offset: 1 in Post-smtp/Post/Post-Mail/google-api-php-client-1.1.2/autoload.php on line 22
  • [Ticket] Silenced PHP warnings in Zend_Mail from ini_set

1.6.23 – 2015-06-27

  • 10,000 installations! – 2015-06-27
  • 9,000 installations! – 2015-06-20
  • [Ticket] Causes bbPress or Buddy Press to generate warning messages. Fixed.
  • [Ticket] User reported error “Fatal error: Internal Zend error – Missing class information” – Whoops, used ‘require’ PostState.php instead of ‘require_once’ PostState.php which was causing errors. Fixed.
  • [Ticket] [Ticket] MyMail Newsletter Plugin for WordPress refuses to use wp_mail. I don’t want to make this a habit, but I’ve integrated Post with MyMail’s proprietary delivery mechanism.
  • [Ticket] Found an environment where the plugin’s call to new Exception was creating PHP Fatal errors. Fixed.
  • [Ticket] Perform validation on all email headers before s