Modern and easy-to-use interface with sensible memory use, html signatures, multi-account support, spell-checker, signing and encryption, deduplicator tool (cleans duplicate emails), google calendar and tasks, contacts, chat, widgets, live backup, auto avatar downloading, improved table editor, built-in themes (inc. Dark Theme), custom themes support, translation of messages.

I use this program primarily because it connects to my accounting software to email purchase orders or invoices. The read receipts are a crucial part of my job in keeping track of order statuses and customer care.

eM Client is modern looking email client, with excellent support for business and home use. Very fast search and great filter options. Support for gmail, Outlook, Yahoo or any other POP or IMAP mail server. With calendar and task management, and nice contact management.