Thunderbird, which several other on this thread have recommended, is solid and reliable. I have been using Tbird literally for years and never had a single problem with it.
Couple of links to check:
https://support.mozilla.org/en-US/kb/installing-thunderbird-linux
https://www.thunderbird.net/en-US/download/
Just checked. Been using Tbird since December 2004 when it was first released.