well
do you need the same users on both servers?
anyway:
on "primary server":
- create a reservation for IP .130 with name accountapp.mechdesign.loc
on the "client" server, setup it with name accountapp domain mechdesign.loc, IP .130, DNS 192.168.125.125
to send emails, on the "client" server, use the primary one as smarthost, authenticating with a valid account
P.S.: when you talk of "member server" you likely talking about M$ servers
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