I've been a long time Thunderbird and Firefox user, considering switching to Mail and Safari. Safari is a topic for another day, but as far as I can see, my only problem with Mail is the ability to customize how long it waits before deleting mail in my Sent and Deleted folders.

I'm very particular about this and have Thunderbird set up to purge Deleted items after 3 months and Sent items after 6 months. I've just found those timeframes to be right where I need them. I see that Mail gives me the option to do this after 1 day, 1 week, or 1 month. That just isn't a big enough window for me. Does anybody know of some kind of "Advanced Config" where it lets me specify the time range I want?