Email Folder Size

I use EF to archive my email. When I hit archive I get a duplicate mailbox which I then merge with the original mailbox. On of those mailboxes has reached 30,000+ items. Is there a maximum size for these mailboxes? An optimum size? Thanks. (OS X 10.8.4, EF 1.6, Mail & Outlook)

There’s no maximum size. Generally speaking, fewer larger mailboxes is faster than more smaller ones. However, some people don’t like any given mailbox to be larger than, say, 1 GB because large files can be unwieldy, e.g. to transfer over a network.

Helpful. Much thanks, Mark