Re: require_rdns being bypassed by MTA relay

"Howard Ogle" <[EMAIL PROTECTED]> writes:
>> "Howard Ogle" <[EMAIL PROTECTED]> wrote::

>> >I have two mail servers (mail.mydomain.com and relay.mydomain.com). Both
>are
>> >configured with FEATURE(`require_rdns'). Mail server "mail.mydomain.com"
>is
>> >the final destination for mail. Reverse DNS checking works all MTA
>> >connections to this machine. However, mail that is relayed through
>> >"relay.mydomian.com" appears to be accepted for relaying to
>> >"mail.mydomain.com" without any dns check. The purpose of
>> >"relay.mydomian.com" is to accept, hold and forward mail to
>> >"mail.mydomain.com" in the event that "mail.mydomain.com" is down.
>However,
>> >I want it to perform the same anti-spam checks as "mail.mydomain.com",
>> >including require_rdns.

>> >The access file in "relay.mydomian.com" contains:
>> >To:mydomain.com RELAY


>> "Neil W Rickert" <[EMAIL PROTECTED]> wrote:
>> You are probably using `delay_checks'.

>> ...

>I don't think I have `delay_checks' anywhere. I'ts not in my
>/lib/mail/cf/sendmail.mc, /lib/mail/ostype/solaris2.m4 or
>/lib/mail/domain/solaris-antispam.m4. I also did a "cat
>/etc/mail/sendmail.cf | grep delay_checks" which returned nothing found.

If you are not using `delay_checks' then your problem is different from
what you describe.

Without `delay_checks', the mail is rejected before that RELAY line
is checked, and indeed it never would be checked if the sender has no
rdns.

Check you logs.  Make sure that sendmail is seeing the IP address of
external system.  Some firewalls and virus scanners make the mail
appear to come from a local system.