CL Simplest SMTP

Description

Send mails throught SMTP server. Simplest option to send mail when hosting or server do not permits send mail or is missconfigured.
We also could to check the SMTP options and check the native PHP mail.

Screenshots

  • SMTP info.
  • SMTP settings.
  • SMTP test with PHP native email and WordPress email.
  • SMTP Help options.

Installation

1 – CL Simplest SMTP can be installed directly through your WordPress Plugins dashboard.
2 – Click „Add New“ and Search for „CL Simplest SMTP“
3 – Install and Activate

FAQ

This plugin adds any options to my database?

If you configure the plugin with constants in your wp-config.php file (see next FAQ), this plugin does not add any data to your database. This is the fastest option because the mail does not need to check data from your database.

If you configure the options from the WordPress admin panel, the plugin will save only one array of options in your database with all the SMTP parameters. The options array saved in your database (wp_options table) is cl_simplest_smtp_options.

Configure plugin with constants.

Configure plugin with constants is the fastest option and also avoids database queries.

We must set these constants in our wp-config.php file:

define( 'CL_SIMPLEST_SMTP_HOST', 'your-smtp-host' ); // SMTP server
define( 'CL_SIMPLEST_SMTP_AUTH', true ); // enable SMTP authentication
define( 'CL_SIMPLEST_SMTP_PORT', 587 ); // set the SMTP port
define( 'CL_SIMPLEST_SMTP_USER', 'your-smtp@user' ); // SMTP account username
define( 'CL_SIMPLEST_SMTP_PASS', 'your-smtp-password' ); // SMTP account password
define( 'CL_SIMPLEST_SMTP_SECURE', 'tls' ); // To use STARTTLS: 'tls'; To use SSL: 'ssl';
define( 'CL_SIMPLEST_SMTP_FROM', 'your-smtp-sender@email' ); // SMTP from email
define( 'CL_SIMPLEST_SMTP_NAME', 'Your Sender Name' ); // SMTP from name

This option is the optimal for security.

This plugin will slow down my WordPress?

No. This plugin is very lightweight and only adds one CSS file and one JS file if you are in the WordPress SMTP options page /wp-admin/options-general.php?page=cl-simplest-smtp and does not add anything to any other pages or on the frontend.

Only adds one database option (first FAQ) with an array of 8 short values and nothing if you configure it with constants in your wp-config.php file (the best option for speed and security).

Can I hide the „Invite me to a coffe“ button?

Yes, of course. You must to define the constant CL_SIMPLEST_SMTP_HIDE_DONATE as truein your wp-config.php file and the button will fly out 😉

define( 'CL_SIMPLEST_SMTP_HIDE_DONATE', true );

But you can invite me to that coffee at any time from https://www.paypal.com/donate/?hosted_button_id=V6U6ZLFHNE6N4

Can I change the log file name?

Yes, the default mail log file name is cl-simplest-smtp-log.txt and is located in uploads folder. You can’t change the location, but you can change the file name if you define the constant CL_SIMPLEST_SMTP_LOG_FILENAME with the file name at your wp-config.php file.

Example:

define( 'CL_SIMPLEST_SMTP_LOG_FILENAME', 'my-cl-simplest-smtp-log-dec-2025.txt' );

Keep in mind that if the default log file was previously created, it won’t be deleted, only the new file will be created and the file that will be deleted on plugin uninstall will be the new defined file.

How can I tell you about a bug, ask for a functionality or contribute to the plugin?

The plugin development of this plugin is managed in this GitHub repository https://github.com/CarlosLongarela/cl-simplest-smtp

You can send us issues, requests or any comments to https://github.com/CarlosLongarela/cl-simplest-smtp/issues or create a pull request to contribute with any new bug fix, functionality or any other code change.

Reviews

24. Januar 2025. 1 reply
I’ve been using Carlos’s SMTP plugin for WordPress, and honestly, it’s exactly what I needed. Super easy to set up, no complicated menus or unnecessary extras. Within minutes, I had it up and running, and it fixed all my email delivery issues like a charm. The best part? It’s lightweight and doesn’t slow down the site, which is a big win. Plus, it works perfectly with providers like Gmail and Outlook—I haven’t had a single issue since installing it. If you’re looking for something simple, effective, and hassle-free, this is the plugin for you. Great job, Carlos!
Read all 2 reviews

Contributors & Developers

“CL Simplest SMTP” is open source software. The following people have contributed to this plugin.

Contributors

“CL Simplest SMTP” has been translated into 3 locales. Thank you to the translators for their contributions.

Translate “CL Simplest SMTP” into your language.

Interested in development?

Browse the code, check out the SVN repository, or subscribe to the development log by RSS.

Changelog

1.2.1 – 2025-01-23

Fixed: Fixed info messages about configurations on config file and database.
Improved: If you set data in constants, settings options are disabled. You need to change or disable constants.

1.2.0 – 2025-01-21

  • Improved: Added log tab to show mail error log files
  • Improved: Added options to show 10, 100, 1000 or 10000 log items
  • Improved: Added options to delete 10, 100, 1000 or 10000 log items
  • Improved: Added a new option to configure log file name with a constant definition

1.1.1 – 2025-01-20

  • Info: Updated plugin page screenshots

1.1.0 – 2025-01-20

  • Improved: Added sections with tabs.
  • Improved: Added a Help tab with FAQs and external tools for checking mail validity and configurations.

1.0.9 – 2025-01-19

  • Improved: Refactorized send_test_mail function.

1.0.8 – 2025-01-18

1.0.7 – 2025-01-18

1.0.6 – 2025-01-18

  • Info: Version upgrade for deploy= 1.0.5 – 2025-01-17 =
  • Improved: Changed selectors to option fields on the test mailing page.

1.0.4b – 2025-01-04

  • Improved: New screenshot on WordPress website and added two new FAQs

1.0.4 – 2025-01-04

  • Improved: Added airmail envelope border appearance to settings.
  • Improved: Delete options from the database on plugin uninstall.
  • Improved: Show error messages when sending fails in the Check Mail option.
  • Improved: Added default mail to send in tests, obtained from WordPress admin email.
  • Fix: Added charset on text/plain test mails and MIME version.

1.0.3 – 2025-01-04

  • Improved: Show the mail test options in a details HTML tag and added CSS to the options screen to improve presentation.

1.0.2 – 2024-12-31

  • Fix: readme.txt typo error.

1.0.1 – 2024-12-31

  • Info: Updated readme.txt file.

1.0.0 – 2024-12-31

  • Info: Initial release.