Mail Mailboxes

I have a McBook Pro and my own dedicated mail server with my own domain. The server only has 1GB of storage so I routinely remove emails and place them in a Mailbox on my mac.

I'm now moving to working between two macs and want to have access to all my past emails on both macs. To increase my storage on my email server is £300 a year as I have to move to a full Exchange account which is over the top.

Can you store Mailboxes in Dropbox? I have a 1TB of storage there.

Or could I get a free Gmail account with 15GB of storage, which is enough and store the mailbox on Gmail?

Any other ideas would be gratefully received.

GP

This may be worthless, because I don't understand most of the stuff you're talking about, but FWIW: I recently changed my Outlook accounts from POP3 to IMAP in order to solve a duplication problem. I was surprised to find the automatic synching between the server and my local Outlook files. I have a strange gut feel that a similar action on your part (if you're not already using IMAP) might help you out.