Sylpheed

Sylpheed is very good, for what it does, but with one very important caveat.
Sylpheed stores all your passwords in plain text.

As to why the authors choose not to use encryption is beyond me. Encrypting user credentials is essential. It should never be optional. FileZilla is another example of an extremely popular program that leaves users exposed in precisely the same way. Tsk!

This lapse in security seems not to bother some people. Although it should. So please be aware and be safe

Finally someone who gets that I just want a simple email client. I use other tools for my scheduling needs and don't need or want them integrated with all email accounts, thank you very much. And Microsoft, I was willing to live with Live Mail until you forced your ribbons on me yet again in your latest update. When will you people get that searching for functionality in an unfamiliar App is way easier with words (like on menus) than it is with obscure pictures on icons?

Dropped using my 365 online email account as I found it slow and clunky.

Sylpheed with an inbox open is using 11.4MB, with the same inbox open via Office365 in Firefox it uses 81.7MB! I just need to check and answer my email - that's it. Sylpheed is fast and does the job.

[Edited by mrbogus, May 26]

This is my current email client. It is simple indeed and I like it. I just want my emails. I switched from thunderbird

Finally a mail client that won't slow down my ancient laptop to a halt when I have stuff open besides it, but with a little problem: If you're using GMail two-factor authorization, you need to create an “app password” for it because Sylpheed can't get the GMail log-in credentials via a web page. It also displays HTML mails in a rather primitive way (like Lynx, Links or W3M on the console).