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MadHatter
Asked: 2015-11-13 05:09:33 +0800 CST

Accept all mail for a domain (from everywhere), forward mail for selected recipients to specific addresses, relay all else to a specific host

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What I want to do is set up a sendmail server that accepts mail from everyone to a particular domain (say, example.com), then for a list of defined recipients sends that mail onto specified third-party addresses, and relays everything else onto a specific IP address.

I've tried this:

[root@splitter mail]# cat relay-domains 
example.com
[root@splitter mail]# cat virtusertable
[email protected]  [email protected]

and forwarding of most of the domain works fine - it's delivered to the host specified by example.com's MX - but the exception ([email protected]) is ignored

I've tried this:

[root@splitter mail]# cat local-host-names 
example.com
[root@splitter mail]# cat mailertable
example.com      esmtp:[1.2.3.4]
[root@splitter mail]# cat virtusertable
[email protected]  [email protected]

and then the exception mail is correctly split off, but any other user is bounced locally (User unknown). I've tried adding this to virtusertable:

@example.com           %[email protected]

but (probably unsurprisingly) this results in rewrite: excessive recursion (max 50), ruleset canonify errors.

I'd prefer sendmail-based solutions, because I can try those quickly. If I don't get any luck with that, I'll open this up to other MTAs. If anyone has any ideas about how to do this, I'd really appreciate them.

centos6

1 Answers

  1. Best Answer

    Let's try this:

    # Assuming example.com is in $=w
LOCAL_RULE_0
Ruser1 < @ example.com. > $*    $@ newuser1 < @somewhere.com. > 
Ruser2 < @ example.com. > $*    $@ newuser2 < @somewhereelse.com. > 
R$* < @ example.com. > $*    $#esmtp $@ [1.2.3.4] $: $1 < @ example.com. > $2

    Naturally this does not scale well if you want to make it workable for more than 10 users and you need to make it work with a map, but I've stopped being a Postmaster since 5/2014 and I am a little rusty. I can make it work with an external map if you like though.

    As always remember that in your sendmail.mc the left hand side of a rule is separated from right hand side with tabs and not spaces, so do not copy-paste. Also remember to rebuild your sendmail.cf afterwards and test using sendmail -bt:

    > 3,0 [email protected]

    If all works as expected restart sendmail.

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