Or, set up a backup MX. For a number of years a friend of mine and I acted as peers for each other. When I was offline for several weeks, every bit of mail I mi

Or, set up a backup MX. For a number of years a friend of mine and I acted as peers for each other. When I was offline for several weeks, every bit of mail I missed got redelivered. Eventually he got tired of running a mail server of his own and I just set up a clone instance on a cheap VM slice, and things Just Work. Yes, servers are supposed to resend when they can't connect, but in practice for those periods where the backup MX was down, I'd still lose some messages I know I should have received.