Outlook4Gmail - Outlook4Gmail provides easy synchronization of your Outlook and Google accounts
MassMailer - MassMailer lets users send mass emails from within Salesforce.
Boomerang for Outlook - Boomerang for Outlook offers email productivity tools to track, schedule and send mails at the right time.
InstAddr - Disposable email address application.
Aryson Outlook PST Repair - MS Outlook PST File Repair tool helps to restore Outlook email data from corrupted or unreadable PST file and save them into a new readable PST file.
Greatmail - Greatmail is an email hosting service provider built for businesses of all sizes.