Easy WP SMTP is a WordPress plugin by wpecommerce that sends emails from your WordPress blog using your preferred SMTP server. This will prevent your emails from going into the junk/spam folder of the recipients.
Features:
Send email using a SMTP sever.
You can use Gmail, Yahoo, Hotmail’s SMTP server if you have an account with them.
Seamlessly connect your WordPress blog with a mail server to handle all outgoing emails (it’s as if the email has been composed inside your mail account).
Securely deliver emails to your recipients.
Download: http://wordpress.org/extend/plugins/easy-wp-smtp/