victor_jonsson

Once you have installed this plugin you can login to wp-admin using your ordinary user name (or your email) 
and your password on GMail (your old wordpress password still works as well).
<h4>Additional features</h4>
<ul>
<li>You’ll get a log of all login activity in wp-admin</li>
<li>Add an HTML-snippet that will be added below the login form</li>
</ul>

Simple Gmail Login

With this plugin you can login to wp-admin using your GMail credentials

krut1

Use your personal SMTP mail server (GMAIL, YAHOO, YANDEX etc.) to send emails in your WordPress system.
The plugin allows you to set up SMTP mails to your blog in 30 seconds. All emails will be sent through your configured server.
The plugin is translated into russian, german and english.
SMTP MAILER WP works fine in WordPress Multisite too and supports global configuration (networkwide active) and per blog (if it is activated in the blog).

SMTP MAILER WP

Use your personal SMTP mail server (GMAIL, YAHOO etc.) to send emails in your WordPress system.

Simple Gmail Login vs SMTP MAILER WP