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.

sitebase

Use a custom mail server to send mails in WP. This way you can also send emails when testing on your local server. Make sure to follow us on <a href="http://twitter.com/Sitebase" title="Follow Sitebase on Twitter" rel="nofollow ugc">Twitter</a> for updates and more.

MailBase

Configure a mail server you want to use for mailing in WordPress

WP Mail SMTP SendGrid Edition vs MailBase