Getting a Gmail account doesn't seem like a big imposition to me. You can use any standalone client to read Gmail. If you don't want Gmail for long term storage you can delete email from Gmail when you retrieve with IMAP. If your hangup is the @gmail.com address, Gmail will consolidate email from a number of different accounts and the sender to those accounts won't know it went to Gmail. While doing all of this you still have Gmails excellent SPAM filtering.