I hope I'm asking this question in the right place, I don't want to offend.

I've recently put together a proof of concept Dovecot IMAP server, and I'm very happy with its performance up to this point. I'm looking into using it to replace our existing POP3 server, allowing users to store email on the server rather than on their local machine, hopefully avoiding loss of data. The big question I have is, is there a realistic maximum realistic folder size, either in reference to number of messages or total file size with Dovecot?

I'm using Maildir and running it on Debian Linux x86. Right now the filesystem is Ext3, although once the system goes live I'd be looking at something a little more fault tolerant and able to handle the large amount of data. Any recommendations you may have on Filesystem choice are appreciated too!

Thanks, Ropetin.