[expert] OT - Backup MX?

[Eric Solberg]

I'm running my Linux server on a PacBell DSL line.  I love the speed but
there have been several outages.  I've found lots of sites that provide
secondary DNS services (PB is doing this for me), but I haven't found
anybody that provides backup mail exchange services.  Is there such a thing?
Do relays hold onto undeliverable mail long enough that this probably isn't
necessary?  Any recommendations?  I hate the thought of having flaky email
delivery.

Thanks,
Eric Solberg