holzhannes

pCoLaSD

This plugin configures WordPress and WordPress MU to use a SMTP server when sending emails instead of the default PHP <code>mail()</code> function.
You will configure your SMTP settings in your <code>wp-config.php</code> file instead of the settings page. 
The advantage is that no admin of your blog can read the settings. 
And you only have to place your settings once in cases of a WordPress MU installation.
A sample configuration:
<pre><code>/**
 * WordPress SMTP server
 */
define('WP_SMTP_HOST', 'mail.example.com');
define('WP_SMTP_PORT', 25); // obligatory - default: 25
define('WP_SMTP_ENCRYPTION', 'tls'); // obligatory ('tls' or 'ssl') - default: no encryption
define('WP_SMTP_USER', 'username'); // obligatory - default: no user
define('WP_SMTP_PASSWORD', 'password'); // obligatory - default: no password
define('WP_SMTP_FROM', 'John Doe <john.doe@example.com>'); // obligatory - default: no custom from address
define('WP_SMTP_REPLYTO', 'Jane Doe <jane.doe@example.com>'); // obligatory - default: no custom reply to address
</code></pre>

WP SMTP Config

Configure an external SMTP server in your config file.

FolioVision

This plugin reconfigures the wp_mail() function to use SMTP instead of mail() and creates an options page that allows you to specify various options.
You can set the following options:
<ul>
<li>Specify the from name and email address for outgoing email.</li>
<li>Choose to send mail by SMTP or PHP’s mail() function.</li>
<li>Specify an SMTP host (defaults to localhost).</li>
<li>Specify an SMTP port (defaults to 25).</li>
<li>Choose SSL / TLS encryption (not the same as STARTTLS).</li>
<li>Choose to use SMTP authentication or not (defaults to not).</li>
<li>Specify an SMTP username and password.</li>
</ul>
Also adds subject to headers for SendGrid Activity Screen. SengGrid is a powerful SMTP service, however it’s Activity Log screen misses the message subjects. Our plugin adds that back in!

WP Mail SMTP SendGrid Edition

Based on WP Mail SMTP. Also adds subject for display on SendGrid Activity Screen.

WP SMTP Config vs WP Mail SMTP SendGrid Edition