[CLUE-Tech] [TECH] - How to resend email in server mailbox

[Garey Hoffman]

Cluebies-

Several months ago, I had a client move their mail internally (on to MS
Exchange). I dutifully changed the MX record to point to the new
location (they use my nameservers). I also added a second MX record with
a lower delivery precedence set to my mail server. Clearly, the intent
was to allow my mail server to act as a backup to capture email case
they're internal server went down. Well, the catastrophic happened over
the last few days with their internal server going down (the MS Exchange
server is not my responsibility). My server dutifully accepted delivery
of their email. I'm now realizing that I didn't complete the setup of
the backup email situation and now have to do it by hand (no fun, but
I'll do it).

I'm looking for advice on how to do both of the following (if, indeed,
I'm even asking the right questions):

1. Deliver the email in their email boxes on my system (only a couple
doxen accounts) to their email server now that it is back online.

2. Setup my mail server (linux with patched versions of pop3d, imapd and
sendmail) so that it can hold mail for my client if their internal email
server is down (MS Exchange) and then deliver it to their internal email
server once it is back up.

I did a quick Google search but I think I'm searching on the wrong
keywords because I'm not finding anything helpful. Any help or direction
would be much appreciated.

TIA,

---Garey