Set up a fully functional mail server on Mac OS X.
Email client with a clean, intuitive interface and end-to-end encryption.
Send newsletters to groups of people.
webmail & calendaring service supports iCal, POP, IMAP
Manage your inbox from the menubar.
notifies you of new Gmail & upcoming Gcal events
Send and receive e-mails.
Attach metadata, due dates, projects, priorities to email.
Encrypt and sign emails with GPG in Thunderbird and SeaMonkey.
Take control of email attachments in Apple Mail.
keep emails on your portable drive