Mailmeteor - Send hundreds of personalized emails with Gmail.
Outlook4Gmail - Outlook4Gmail provides easy synchronization of your Outlook and Google accounts
GMass - GMass allows you to easily schedule emails, send out mass emails and mail merge campaigns and more with Gmail! Click here to learn about more features!
Boomerang for Outlook - Boomerang for Outlook offers email productivity tools to track, schedule and send mails at the right time.
Email on Acid - We make the send button safer. For every campaign, every message, and every inbox, Email on Acid has the time-saving tools you need to put your best email forward.
BlueMail - BlueMail is an email management app for Android, iOS, and Windows.