Close folders in Mail like in Outlook?

[sv02]

I'm wondering if I can do something in Mail that is analogous to Outlook...

Background: at work (PC laptop) I learned that Outlook would lag when it constantly tried to sort all the PSTs/folders that were sitting in the view panel. If I right-clicked to "close them", the messages were fine as the PSTs still existed on the computer, but Outlook no longer took time processing the presence of that folder. I never had to move any files though.

I haven't figure out how to do this with Apple Mail, if possible? I have folders/conversations from years ago that I don't want to delete, but now Mail is taking longer and longer to close down, and I'm thinking the size of it could be the problem (my Mail folder in the Library is 5+GB)..... I tried searching for some option to do this but can't find anything...... I understand in Library>Mail all the mailboxes show up. I'm wondering: do I have to physically move them from there to have them not show up in Mail, and move them back if I want to search for something? Or is there a way to leave everything there but not have Mail keep seeking them out from the main screen?

Hope this makes sense!

[earthsaver]

I don't think there's exactly an equivalent to Outlook for what you seek, but you may benefit from forcing Mail to reindex all of your messages. Quick Mail and move Envelope Index out of ~/Library/Mail. Then start Mail again and it will prompt you about reimporting your messages. Let it go and see if this affects your scenario.

Also read in Mail Help about archiving mailboxes and interaction with Time Machine.