WordPress Simple SMTP

Mô tả

Adds a simple, no-fuss SMTP settings to your WordPress installation that lets you define custom settings, which is especially useful for hosts with no control over the php mail functionality.

Environment and constant overriding (optional)

This plugin will prefer environmental and constant-stored values over the plugin-saved equivalent settings, making it easier to use this plugin via deployment.

These can be either stored in your systems env setup, or in wp-config.php as define( 'SEE_BELOW', 'your_value_here' );.

Accepted Parameters

  • SMTP_HOST (string) Mail server hostname.
  • SMTP_PORT (integer) Port address (usually 25, 465 or 587).
  • SMTP_AUTH (integer, 1 or 0) Pass below credentials to your mail server.
  • SMTP_USER (string) The mail username for this account.
  • SMTP_PASS (string) The password for the mailer account.
  • SMTP_FROM (string) Enforce all emails come from this email address.
  • SMTP_FROMNAME (string) Enforce all emails to have a certain email name.
  • SMTP_SEC (string) Use a particular email security method (accepts ‘def’ (default), ‘ssl’ and ‘tls’).
  • SMTP_NOVERIFYSSL (boolean) Disable validation of the SMTP server certificate (not recommended).
  • SMTP_LOG (boolean) Controls the logging capability and visibility.
  • SMTP_DISABLE (boolean) Disables the mailer. They will still be logged if enabled, but won’t send out.

It is recommended to store at least SMTP_PASS in your wp-config.php file (with the correct file permissions set). If the openssl extension is available, the plugin will attempt to encrypt the password in the database.

Hỏi đáp

How do I fix SMTP errors?

This plugin works by instructing PHPMailer – the mail library WordPress have chosen – to use SMTP mode, and adds in the settings you choose. 9 times out of 10, the error messages you receive are configuration errors. PHPMailer provides a good guide to help you figure out these problems.

Troubleshooting – PHPMailer.

The one instance where an SMTP error can be caused by this plugin is if the SMTP password is stored in the database when the secret keys have been regenerated. You will need to re-save the password to refresh the encryption keys.

You can always get assistance from your host and/or SMTP service provider.

One or more of the settings are greyed out

This plugin supports being overridden by DEFINE, so please check to see that you are not setting a define for a WP Simple SMTP option. These are most commonly stored in the wp-config.php file.

The over-ride hierachy is as follows, with top being the most important.

  • Environmental variable.
  • Constant variable (wp-config define).
  • Multisite network settings.
  • Locally-configured settings.

How is the SMTP password stored?

If openssl is available to PHP, then the password will be encrypted (not hashed) when stored in the database. If unavailable, the SMTP password will be saved into the database as plaintext. The more recommended way of storing the password is to define SMTP_PASS in your wp-config.php file, which should already be locked and inaccessible from the front-end.

Can I change the amount of entries shown in the log view?

This can be adjusted by the ‘simple_smtp_log_table_max_per_page’ filter. Returning an integer value to this filter hook will adjust the table page limit.

Does this plugin work on WordPress Multisite?

Yes. Each site can have unique settings, unless overriding is on. The network will use the main site settings, so network admin emails will show up in the main site log.

Since version 1.2, network-activating the plugin grants special configuration options for super administrators. This includes the ability to set overrides and configure site admin access.

Why do I see capital texts next to the input boxes? (Debugging disabled input boxes)

To help diagnose disabled input boxes, when the WordPress site is in debugging mode, the input fields will show a small debug text to indicate where the setting came from.

  • CONFIG is the standard method of saving settings via the admin menu.
  • CONST are overrides typically set in either wp-config.php or your theme’s functions.php.
  • MULTISITE are network-defined overrides set in the Network Mail panel.
  • ENV are pulled from the machine/server environmental settings.

Can I report an issue, or contribute to development?

Yes! Please see our GitHub repository here for writing issues and/or making pull requests.

Đánh giá

14 Tháng Chín, 2021
Simple to use, no fuss. Easy to set up with constants. Support multisite!
Đọc tất cả 2 đánh giá

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Nhật ký thay đổi


  • Add: Filter for the log entries. Thanks to Kebbet #57.
  • Change: Input boxes clearer and more WordPress-standardised (#51, #52).
  • Fix: Use network_admin_url instead of crafting a URL. Thanks to Kebbet #53.
  • Fix: Notice when saving settings without password being set (#44).


  • Change: Multisite listing table improvements. Thanks to Kebbet (#50).
  • Fix: Line break issue when viewing emails in the site log. Thanks to Kebbet #47.
  • Fix: Missed localisations in the multisite table. Thanks to Kebbet #45.


  • New: Multisite settings for admin visibility and override settings (#6).
  • New: Sites in debug mode will show what stage has set the configuration item in the relevant box.
  • New: For sites using logging, ‘Erase Personal Data’ will remove requested email address entries from the log (#37).


  • Verified working with WordPress 5.8.


  • Verified working with WordPress 5.7.
  • Fix: Crash when sending emails with the email system disabled (#35).


  • New: You can now disable emails (#9).
  • New: Attachments are now logged, and will be resent if they are still available on the system (#14).
  • New: Key change detection when SMTP password encryption is used, to warn user the email dispatch may fail (#28).
  • Change: Custom HTML removed in favour of translatable HTML test email. Thanks to Kebbet for implementation (#26).
  • Fix: JavaScript error when viewing emails (#24).


  • Fix: Quick config translations not loading, and missing i18n entities. Thanks Kebbet (#21).
  • Fix: Incorrect pagination if the log count was divisible by 5. Thanks Kebbet (#18).


  • Fix: Text-domain mismatch causing translations not to load in correctly. Thank you to Kebbet for the fix (#19).



  • SMTPSecure is now a configurable option (#11).
  • Log entries can now be deleted (#13).


  • When openssl is available, the password stored in the database will be encrypted.
  • Added a quick configuration option, to guide SMTP setup (less Googling).


  • Confirmed working with WordPress 5.5.1.
  • Added option to disable SSL verification.
  • Multiple emails can be used in the test functionality.


  • Independent log tables deprecated for CPT.


  • Changed display format of email log.
  • Limit resent emails to hourly.


  • Table is created or deleted upon plugin state change.


  • Changes to test emails.
  • Log view changed depending on header.


  • SMTP error logging.
  • View and resend emails.
  • Test email settings.


  • SMTP configuration handling (overrides mail()).
  • Optional SMTP logging (basic functionality).