best way to receive email for multiple domains with multiple user accouts into rails app

Question

hi all

I have a cms that runs on multiple domains and therefore needs to pull emails into the app for multiple email addresses.

I have setup rackspace email for a hosted email solution and am trying to find the best way to pull the emails into my app from all the mailboxes.

Should i be using pop3 or imap ? should i be pulling into a que system then into rails app ? Is there a gem / plugin for this ?

thanks alot for help in advance Rick