If you're as picky as I am, and if you deal with as much mail as I do, options are severely limited. Seriously, I've yet to find a decent e-mail client. I switched to the Mac from Windows late last year, and was a very reluctant Outlook user. Although I hated it, it was the only client robust enough to handle the volume of mail I threw at it in a way that was comfortable for me.
When I switched to OS X, I tried Mail.app and loved its simplicity but quickly realised it's not really very robust and I need "workarounds" for every little thing. (For example, a big one for me is that I like marking my mail read manually, and manually only. The only way to keep Mail from automatically marking my mail read is to get rid of the preview pane - ARGH.) I then switched to Entourage. Entourage was actually pretty cool, if kind of bloated (but since everybody's needs differ, I kind of expected that). Unfortunately, with the volume of mail I have (about 3GB), it began to crash incessantly (Intel Mac, Entourage ran in Rosetta, as you already know). After my last overhaul, I switched back to Mail.app. It's too simple, yes, but it doesn't crash all the time. It'll do until I can find something better.
The options I'm looking forward to evaluating are:
- Leopard's Mail.app
- Office 2008
- Penelope (Eudora gone open source)
The reasons that it's best to stick with Mail.app for now:
- When another client that suits you is made available, you can be certain it'll import from the latest version of Mail.app without a problem.
- If you can't live without Entourage's unified tasks-contacts-mail interface, check out Crm4Mac, which was, the last time I checked, on sale for 50% off.
Hope that helps.