Multiple color themes, including an eye-saving dark theme
Fast search, including search within attached documents
Beautiful calendar interface with multiple calendar views
Integrated email translation
Automatic spell-check
Message encryption (S/MIME and PGP)
PGP key sharing service eM Keybook
All attachments view to manage attachments from all your accounts
Watch for reply to important emails
Snooze incoming emails
Delayed send
Advanced email rules
Templates, signatures and QuickText snippets
Deduplicator tool
Full touch support
Many options for sorting and categorization
Sidebar for quick access to contact details, agendas and invitations
Meeting scheduling
Support for internet calendars
Automated periodic backup of data