Advanced WordPress Email Delivery
All in One email for WordPress is an extension for WordPress email sending that adds features missing natively:
“From” email field editor to replace WordPress defaults.
SMTP support to allow sending emails through an external server.
HTML emails with stylish template instead of plain text.
WYSYWYG template editor and previewer.
System emails editor (new user registration, password retrieval, comment notifications, etc)
WP-Ecommerce and BuddyPress emails theming.
SMTP authentication and SSL.
Built-in test email sender to catch errors early.
Simple and sleek interface.
Please note that Advanced Email delivery is an outgoing emails tweaker that helps you to send emails when you need mode flexibility than standard WP options provide. It is not a WordPress-based email client or mass-mailer.