MailMate

MailMate is an ambitious, powerful email client for OS X. It is designed for and only supports IMAP while still working in full when offline.

MailMate has state-of-the-art searching capabilities and correspondingly advanced smart mailboxes. Extensive keyboard control and dynamic signatures ensure a highly efficient workflow when reading and answering emails. Alternative message viewer layouts and a browser-inspired design ensure easy and rapid access to related messages. Features Universal mailboxes: One Inbox for all of your IMAP accounts. Extensive keyboard control: Switch mailboxes or move messages using the keyboard only. Advanced smart mailboxes: Make any/all combinations of other (smart) mailboxes and use any/all combinations of matching conditions. Tags: Organize your emails using tags. Link-searching: Search for related messages using search links. Dynamic signatures: Default signature based on the history of sent messages. Notifications: Multiple dock/menu bar counters and Growl notifications. Mailing list support: Mailing list messages are automatically organized in smart mailboxes. Alternative message views: Easily browse email statistics or use thread arcs to navigate in a message thread. SpamSieve integration and full control over image blocking. Support for both S/MIME and OpenPGP. Support for tags using IMAP keywords for synchronization. Support for Spotlight searches.