At the last PMUG SIG we talked a little about Gmail. Jim Hamm noticed that he hasn't seen any spam come in through his Gmail account while he does get a lot of spam through other mail account. I, too, have noticed the same thing. So I experimented a little today and set up my Gmail account to pull in all my email from my other accounts - except Yahoo - and now when I get mail in Mac Mail, all that mail comes in to one place because I pull it all from the Gmail account.
I have four separate accounts set up in Mac Mail, Gmail being one of them. The only account that is active is the Gmail account. The others are now just place holders. When mail comes in, I have rules set up to sort my inbox. Each mail item is moved to a folder based on the information in the To: and Subject: lines. Really nice! One place to read all my mail, even when I'm away from home - because I can now login to my Gmail account online and read everything.
Another plus! I set up Mac Mail to send through my Gmail account as the default sender, but I have the other accounts waiting in the wings in case there's a delay in sending through Gmail, and I am prompted to try another server - or I can just wait it out and it will get sent eventually.
Of course, I do have to log in to the Gmail account occasionally to clean up the junk folder. Even if I don't, it will clean itself up in time. No worries, mate!