Emails client

Claws Mail ​

​Official Site｜Download Page​

An email client and RSS reader, based on GTK+, featuring extensibility, robustness and stability

​MailBird ​

IMAP and POP3 email client, featuring customization, complete touch support and multiple language support.

​Nylas N1 ​

An extensible desktop mail app built on the modern web.

Thunderbird ​

also Mozilla Thunderbird

​Official Site｜Download Page​

Email client with minimalistic design with powerful address book, emails filter, RSS reader, etc.