Re: Secondary MX user list filter for Sendmail

[Crist Clark <crist.clark () globalstar com>]

Todd Vierling wrote:

> A colleague asked me offlist about how to make a Sendmail secondary MX
> properly return 550 for invalid recipient addresses.

[snip]

For those with an LDAP directory containing mailbox information, I'd
recommend using sendmail's built-in LDAP capabilities. I've found it
a good way to test for existence of mailboxes at border MTAs. My
example (NOTE: I've pulled out the LDAP stuff from a rather complex
.mc file, and it can be done in a more straightforward way without
all of the other hacks I'm simultaenously supporting in my rulesets),

LOCAL_CONFIG
Kldap_rcpt      ldap -b dc=example,dc=com -h directory.example.com -T<TMPF> -v mail -k 
(&(objectClass=inetLocalMailRecipient)(!(inetUserStatus=deleted))(!(inetMailGroupStatus=deleted))(|(mail=%0)(mailAlternateAddress=%0)(mailEquivalen
tAddress=%0)))

LOCAL_RULESETS
# Check if local addresses really exist on central server.
SLocal_check_rcpt
R< $+ >                 $1
R$+ @ $=R               $: $1 @ $2 $| $(ldap_rcpt $1@$2 $: <NOMATCH> $)
R$* $| <NOMATCH>        $#error $@ 5.1.1 $: 550 User unknown

--
Crist J. Clark                               crist.clark () globalstar com
Globalstar Communications                                (408) 933-4387

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