I've defined SMART_HOST to be a specific server, lets call it foo.bar.com. However, when I send a test mail using 'sendmail -t', sendmail tries to use mx.bar.com, which subsequently rejects my mail. I've verified that foo.bar.com works and that mx.bar.com does not work (yay telnet). I've recompiled sendmail.mc vi make, make -C and m4. I've verified the DS entry in sendmail.cf. I've restarted sendmail correctly. I'm not sure how to proceed at this point. Any ideas?

Here is my SMART_HOST line:


...and here is the result of a test mail. It never tries to use foo.bar.com, instead it uses mx.bar.com.

$ echo subject: test; echo | sendmail -Am -v -flocaluser -- myaddress@somewhere.else.com subject: test
myaddress@somewhere.else.com... Connecting to mx.bar.com via relay...
220 mx.bar.com ESMTP
>>> EHLO myhost.bar.com
250 SIZE 52428800
>>> MAIL From:<localuser@myhost.bar.com> SIZE=1
250 sender <localuser@myhost.bar.com> ok 
>>> RCPT To:<myaddress@somewhere.else.com>
550 #5.1.0 Address rejected.
>>> RSET
250 reset
localuser... Connecting to local...
localuser... Sent
Closing connection to mx.bar.com.
>>> QUIT
221 mx.bar.com

And last, here is a test mail sent using foo.bar.com:

$ hostname
$ telnet foo.bar.com 25
Trying ***.***.***.***...
Connected to foo.bar.com (***.***.***.***).
Escape character is '^]'.
220 foo.bar.com ESMTP Sendmail 8.14.1/8.14.1/ITS-7.0/ldap2-1+tls; Tue, 21 Dec 2010 13:27:44 -0700 (MST)
helo foo
250 foo.bar.com Hello myhost.bar.com [***.***.***.***], pleased to meet you
mail from: localuser@myhost.bar.com
250 2.1.0 localuser@myhost.bar.com... Sender ok
rcpt to: myaddress@somewhere.else.com   
250 2.1.5 myaddress@somewhere.else.com... Recipient ok
354 Enter mail, end with "." on a line by itself
250 2.0.0 oBLKRikZ003758 Message accepted for delivery
221 2.0.0 foo.bar.com closing connection
Connection closed by foreign host.

Any ideas?



Sendmail may be performing an MX lookup on the domain, which is not necessarily what you want. Enclose the hostname in square brackets to prevent this.

  • that did it... at least for the test mail :) thanks – daniel Dec 21 '10 at 21:43
  • This works when using -Am, but reverts back to mx.bar.com if I don't specify -Am. Is there a way to force sendmail to not perform an MX lookup system wide? – daniel Dec 21 '10 at 21:55

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