I have all my domains set up on my Google Apps Premier account. That way I get to use the great Google spam mail filters and I don’t have to run and maintain my own mail server and spam filters, which is definitely nice, I can play with that sort of thing at work instead.
When I’m on my laptop I almost always use Mail.app, but on all other computers I use the web interface.
All mail filtering is done serverside by Google, all Gmail tags appear as folders in Mail.app, and I keep as much logic on the serverside as possible, storing everything serverside, never deleting anything.
The “All Mail” mailbox is then used as trash by selecting the mailbox in the mailboxes pane, clicking “Mailbox” → “Use This Mailbox For” → select “Trash”. This makes deleting a mail in Mail.app equivalent to archiving it (‘e’ with keyboard shortcuts enabled) in the web interface. One problem though; I just discovered that Mail.app no longer displays the “All Mail” folder on Snow Leopard. Maybe that happened in the upgrade from Leopard… let me know if you know.
In addition I set up Gmail filters so that mailinglist email gets tagged with the list name and then archived straight away, so I never see them directly in my inbox, only when I dive into the appropriate folder. This way the mail that appear when I open Mail.app is something I have to read and process, and I either do this straight away and then delete it (archive), or I flag it (⇧⌘L) to return to it later, as this is much easier than using an “Action” folder like the inbox zero system prescribes. I really hate moving mail between folders manually, it’s a high cost operation.
And that’s it, that’s how I handle mail. Simple and efficient.
I like the paid version of Google Apps for the lack of advertising and extra features. It was a pleasant surprise when I found out that you could have as many domains as you wanted on the same Google Apps account, the only limitation being that you’re not given complete liberty at administering mailboxnames acrosss all domains, meaning that if you have the ‘
asdf’ mailbox on one domain, you have it on all of the other domains too. No problem in real life though.