I’m on a Mac and yet I’m still using Eudora. I have to run it in a Snow Leopard (10.6.8) virtual machine but it’s worth it.
I’ve been using Outlook for about 25 years now and I loathe every microsecond I’m forced to use it. It is easily Microsoft’s worst modern product, and is in the running for Microsoft’s worst product of all time (I suppose that Microsoft Bob would be good competition). And I say this as someone who generally likes Microsoft products. Outlook started awful and gets worse every year of its existence. I’ve probably used a dozen different email programs and Outlook is easily the worst. If it were unable to send email, then I could say that its one redeeming value is that it is not actually an email client, but it doesn’t even have that going for it. It’s awful enough that I don’t wish it upon my worst enemies, but not because they don’t deserve it–it’s because the UN would classify it as a war crime.
I hate Outlook. I can’t believe it’s a corporate standard, it’s incredibly clumsy.
I think I’d prefer Pine.
I have used Pine, and it’s fantastic in comparison.
Outlook is fractal in its awfulness. No matter how closely you inspect one of its idiotic features, it expands further out into a kaleidoscope of stupidity. You can just keep zooming in forever and it gets worse and worse.
Wow!! I have no words!
I am absolutely no fan of Microsoft. I loathe their lack of testing and disdain for quality. But Outlook has always been a great product for me. Furthermore, a good friend of mine who runs a home-based consulting business has been using both Outlook and Excel as essentially her customer database, and I can only dream of bringing in the millions that she has over the years.
So I’m going to suggest that your use cases are radically different from those that some others of us are accustomed to, including the vast number of large enterprises that use Outlook+Exchange. Heaven forfend that I should ever be a defender of Microsoft, but really, what on earth are you talking about?
Runs just fine on Windows 11! 
I miss mh.
When it ceased to be a useful option it was like switching from a stick shift to a soulless slush-box.
Takeaway is that personal preference exceeds any useful opinion on what is best or most useful.
I’ve used eMClient for ages and have never regretted it. Now in Windows 11. Highly recommended, and great Tech Support (for questions, never had a problem with it).
Yeah. !$%! on you. You folks aren’t subject to ever-changing processors. Apple has gone from 68K to PowerPC to Intel (like you folks use) to Apple silicon. Apple isn’t much into legacy. And Eudora was last compiled for the Mac for PowerPC processors.
I still run some 68K applications that work better than modern stuff.
Well to be fair to Apple, they don’t own Eudora.
But Eudora didn’t die. It was open sourced after Qualcom abandoned it and gave the rights to the Computer History Museum. You can get the successor: Hermes Mail for free.
So many alternatives for desktops and laptops, nice and interesting. Haven’t followed the developments in the field, mostly out of inertia. But what do you use for your mobile phones?
Doesn’t appear to have a MacOS version 
Downloaded Tbird. A little issue with putting on my second yahoo account but quickly resolved. Looks just like I remember.
I love your way with words!!
FTR, I should add an important qualifier to my praise of Outlook. I’m running Office 2003 on some computers (with the add-on for XML file formats) and 2007 on others. If Microsoft has followed their usual practice of bungling later releases after achieving an optimum level of useful functionality, it’s entirely possible that the latest versions of Outlook are a bloated mess. Also, I use it almost exclusively for email and not for its various other functions. From that standpoint the versions I mentioned are perfectly fine programs with good usability, IMHO.
Oh, tell me about it. I blame Gmail. When most people were using a big mix of clients, I could get away with mh, and the few html-only emails were easy enough to deal with. So many of those clients did poorly with html, that lots of places wouldn’t use it. Then Gmail just handled everything mostly fine, so there was no reason to send a text version of a message.
I long for the simplicity of
refile +francis $(pick -from vaughan)
Sometimes, when I’m really tired or a bit drunk, my fingers try to type inc.
Hmm. Well, Mutt supports IMAP out of the box and can be configured to work with multiple accounts.
K9
It nearly stopped working, and was years out of date. Then the pandemic happened and the developed updated it.
Note that K-9 Mail is now being run by Mozilla and is slowly being turned into Thunderbird for Android (to which it may or may not be eventually be renamed).
What’s mh?