Outside Vendor to be backed up locally

I am currently using a third party company to hold my e-mail & web site. I manually do a back up of the site every now and then, but I use IMAP for my e-mail. They currently hold all of my e-mail on there systems and I would like to do something about that. I do not like POP mail systems because I use 2 diffrent computers so I have them set up as IMAP to just pull from the server. Is there any way that I can make 10.2.6 Server retreive my e-mail for me and hold it locally on my server so that if there server goes down I will be able to still get to my e-mail that would be backed up to my local server?