[ZenoArrow]

For email clients, Thunderbird is still being developed (latest release was from less than a month ago):

https://www.mozilla.org/en-GB/thunderbird/

Also, the V1.0 release of Mailpile is meant to be coming soon:

https://www.mailpile.is/

https://github.com/mailpile/Mailpile

For setting up your own email server...

https://mailinabox.email/

http://www.iredmail.org/