It looks like my honorable associate Joe Brockmeier has also discovered the beauty of the offlineimap utility, which is one of my favorite productivity tools as well.
If you’ve been reading my blog for some time, you’ll know that I’m a big fan of using offlineimap in cahoots with the Mutt mail reader and postfix as a local server. Joe writes about using msmtp as a sending utility, or mail transfer agent (MTA) as mail geeks say, but I prefer postfix because it gives me the ability to do slightly more sophisticated deferrals.
If I’m on a plane or otherwise offline, I like to be able to simply hit send without worrying about my connection status. When I connect to a network later, my configuration allows my email to flow to the proper relays as needed. If my system can reach GMail, that account’s email gets sent. If my system can connect to Red Hat’s VPN, email from my Red Hat account gets sent.
In July 2009 I wrote more about this setup here, here, and here.