abc.com MX perference = 10, mail exchanger = MAIL1.abc.com
abc.com MX perference = 20, mail exchanger = MAIL2.abc.com
Independent Mail server
MAIL1.abc.com (Exchange 2007)
MAIL2.abc.com (Linux postfix server)
Supposed some unknown email or MAIL1 email service down. Based on MX record, those email will be auto tried to send to MAIL2 server. The both server have their own user accounts, so those email are also rejected by MAIL2 server.
As I know, some ISP will have some services to hold those unreceived email, and then send back to clients when MAIL1 service is normally restarted
1. Can I set MAIL2 for temporary pick up all MAIL1 incoming email when MAIL1 is down, same as ISP service? Is it possible (MAIL1 = Exchange / MAIL2 = Linux) or (MAIL1 & MAIL2 are both running Exchange) ? If worked, what I need to prepare?
2. If not, how can I prevent all MAIL1 unacceptable email redirect to MAIL2?