I think people were still using AOL and Compuserve in the days of OS 9.

I used Eudora (1988 – 2006) until Qualcomm abandoned it, but it occasionally had the problem. When I switched to Mail, I basically set it up to look as much like Eudora as I could.

Claris Emailer.

Apple didn't buy Claris. Claris was formed by Apple as their software division in 1987. It is a wholly owned subsidiary. Then Claris bought FileMaker, and the rest is history.

I used to use Claris Emailer, ClarisWorks and Claris Homepage.

These days for email I use Outlook 2011. I had been using Entourage before that. I tried Mail out briefly in the early days of OS X, and didn't like the way it handled HTML formatted mail, so I stayed with Entourage.

Every so often I think I'll give Mail a try, but at this point it's a paint to try and import everything and get it all set up the way I like it. Subsequently I also don't use Calendar (iCal), or Contacts (AddressBook) very much.

It was the days of Outlook Express for Mac which lots of people used ;-) and Entourage/Outlook 2011 are not exactly the sharpest diamonds in the pack as far as HTML formatted email either. We had to jump through hoops to try and send pre compiled HTML formatted mails as they both use the Word HTML rendering engine which frankly is so bad !

For me, Mail was massively improved with Lion. I think I posted here about my experiences.
If you use the Smart Mail Boxes, that's a very good way of sorting out your Inbox without ... sorting it out.:o

For instance, I have one Smart Mailbox for FaceBook incoming. I can easily select the contents and delete them all when they get too numerous. That's them taken care of locally, and on the IMAP server. Other Smart Folders for known work addresses, various friends, the university, etc, etc.
You can also see new emails in each Smart box with a number beside them.

Flags are also useful for mails that need responding to. They automatically appear in a Flagged Smart Folder. And you can archive mails into folders on the Mac. (Or on the server, too!)

I now have 2 IMAP accounts and all my mail synced between three devices, and it works beautifully.

I have had a lot less issues moving 90% of my users to Apple Mail from Entourage/Outlook 2011 over the last few years. I would say that Mail is probably the best option for email on Mac overall. My only gripe is i would like a unified workflow like Entourage/Outlook with Mail/iCal/Contacts/Reminders etc all in one window/app Mail ! This is the most requested feature from switchers ;-) 4 apps to flick between is not as efficient as 1 ! (I should add that of course the 4 apps would be separate still but bringing a unified view into mail would be a great feature.

I agree that Mail 10.7/10.8 are mature apps that fit the bill for email management with IMAP/POP and Exchange.

That's exactly why I hate Outlook. It's too modal, and you can only be in one place at a time. It reflects the Microsoft mentality of throwing the kitchen sink at a problem--which results in a Frankenmess of a program with weird inconsistencies. I can drag and drop in some places but not all. My scroll wheel works in most lists but not all...and more. I like Apple's "unix-style" of making small, self-contained applications that are polished and work together.

Agree with Chabig. The perfect and hated example of multi functionality in OS X is iTunes. Way too much crap going on.

Different strokes for different folks. Overall I would still want the separate apps like it is now. But many users have voiced to me a unified mail/contacts/calendars/tasks would be useful.

But what's the definition of unified? Do the functions have to exist in a single window, or is it more important for the functions to be integrated so that they work together? Outlook suggests the former. Mac OS follows the latter philosophy.

I am saying the ability to flick between the these apps content in 1 window would be useful. Some users do not have screen real estate and App switching is OK but not as good as a quick icon click in a unified window. I am not trying to say which is better or worse so do not want to get get pulled into a tit for tat or a Mac/Windows discussion. Apple have done various things to "unify" but in a kludged way like "Mail to dos" and a "contacts" button.

I think "unified" in this context is being used where we often refer to "convergence." Things like kitchen appliances with a built-in television. Or using what NovaScotian mentioned, using music software for syncing apps, music, movies, email, contacts, podcasts, and documents to an iPhone/iPad. Generally, products like this don't go over well. Obviously, the Outlook setup on Windows and iTunes are exceptions in that they've been widely adopted with minimal complaint considering the size of the install bases.

Personally, I don't tend to like the idea in my software. But that's predictable since the Apple OS has always been application-focused and it's what I've largely used throughout my life. Considering how rarely I actually open Address Book or iCal, despite using them, I certainly wouldn't want it as part of my email client (note, too, how there was never a positive reaction to RSS in Mail). But if I'd been in Windows since 95 or so I probably would feel differently.

I think it's one thing to give people another way of doing things (think touchscreen phone vs. QWERTY phone), but many people don't respond well to shifts in how they view and manage data they use daily. I would expect many (most?) to be uncomfortable coming from years of Outlook over to the Apple setup with distinct applications for calendar, contacts, email and reminders.

I'm going to write my own in FileMaker. (I've already done the bare bones of it, it needs some GUI work and some scripting for filtering).

I'll have to start using it for real as soon as I'm forced out of the Rosetta-capable world of 10.6.8 and (therefore) Eudora.

Can confirm Apple Mail is doing something not quite good. I run a) Mac OS 10.8 and 4 different accounts at b) 4 different email providers. c) All are IMAP. Apple Mail just dropped everything, and I've went two rounds now just filling in all passwords again and they're lost as quick s they're put in the system. So No – it is not about POP versus IMAP, and No – it is not about a single email provider faulting either.

Yes, mrFisck, my conversation with AppleCare pretty much confirmed that. Mail's been an absolute beast on this issue.

I've recently downloaded Postbox and am trying it out. Impressed with the features available, and hoping it's a viable option.

Postbox seems to be gMail only. I've been using MailPlane for that and like it well enough.

That's not correct. Here's what it says on the Postbox web site, right after touting the support the application has for Gmail-specific features like labels:

Quite nicely done, I agree, but I won't be switching because I have a ton of filters aimed at Junk and a large set of "On My Mac" folders for two POP accounts. Neither your filters nor your local folders are imported which leaves a new user with a lot of work to do writing a script to move all that stuff (Postbox is scriptable, though I didn't study its dictionary). It does do a great job of importing your accounts, however -- it was immediately bang on, fetching mail from them. Price is right, too.

Where are the Mail preference settings?
 

Does Mountain Lion's Mail 6.0 have Preference settings somewhere? I'd like to tweak the application -- in particular, to get it to try a couple more times to get mail from an account before generating the rejected password error message and to try to configure the accounts differently (some I would like to query for new mail less often than others). I've looked for .plist file or something like it but not been able to find anything like a configuration file. Any advice?

Try looking at the actual Preferences options rather than editing plists. From the Mail menu, select Preferences, then look under Accounts.