Author: Patrick Starrenburg Date: To: exim-users Subject: [Exim] Redirecting SMTP session to different server based on RCPT address
I am interested to see if this is feasible...
I want to see if it is possible to redirect an SMTP communication from one MTA
to another based on RCPT address.
Situation is multiple regions around the world with company HQ in one region.
HQ wants everyone to have email address in form - user@??? - only
problem (for me) is that this will mean that our region (we are not HQ) will
have all our mail go through the HQ region's mail server(s) which are.......
not as "discerning" as the server in our region. We use Exim as Internet
gateway mail server to corporate mail system and HQ uses TrendMicro SMTP server
which, in my opinion, as a mail server is pretty brain dead - it'll just about
accept any RFC clueless MTA which connects to it. It is more focused on
stopping viruses than being a full featured mail server. It then passes mail
onto corporate mail system.
Is it possible - to / what platform would be required / has anyone done this /
anyone have any ideas - have a setup where:
based on a lookup of the RCPT address (most likely LDAP against MS Exchange)
the MTA could *redirect* the SMTP communication to another SMTP server. So MX
records for domain point to, say, server mx.headquarters.company.com which
during the SMTP coversation tells (bounces) the calling MTA to another MTA at,
say, mx.subsidiary.company.com which is located elsewhere in the world. Note I
mentioned redirect, not route. This means the first MTA does not accept the
message and route, but after RCPT phase redirects calling MTA to another MTA
which accepts mail for domain company.com.
The possibity of sub-domaining, which could have easily solved this problem,
by having region1.company.com etc. like eu.company.com, us.company.com,
ap.company.com point to MX records for specific region was rejected.
