Sending SMTP mail to Microsoft exchange server

[David Pace]

I am attempting to set up sendmail to forward all smtp mail to our exchange server. I can successfully send mail via exchange to addresses in my domain. The problem comes up when I attempt to send to an address outside of my domain. Sendmail attempts to resolve the address. When it fails, it just queues the message. I need sendmail to simple relay all smtp messages to exchange.

[Steven E. Protter]

modify this file:

/etc/mail/sendmail.cf

Change

DS

to

DShostname_of_exchange_server

or
DS
[IP address of exchange server]

The latter method will work even if DNS is down on your network.

The Exchange server must be configured to relay mail from your HP server.

/sbin/init.d/sendmail stop
/sbin/init.d/sendmail start

I believe the above is a soluition to the issue.

To test the configuration:

sendmail -v -d8.99 -d38.99 someone@your.net
Type some text

.





means hit enter.

good luck and regards,

SEP

[Jim Mallett]

Dave,

Steve's on the money as far as the settings go, I just wanted to add: Pay special attention to his line about the Exchange Server needing to be setup to accept relays from the HP box.
I suddenly saw the same symptoms you have only to find out our Exchange Admin had turned off relaying because of a pretty bad (external) spamming incident.
There should be an exception list that you can add your HP box too that will allow relaying.

Also, /var/adm/syslog/mail.log may shed some light on the connection failure with the Exchange server.

Jim

[David Pace]

I have set the DS value in sendmail.cf to the address of our exchange server. Mail within our domain seems to work okay, but address outside of the domain get name server timeouts and the following message:

Transient parse error -- message queued for future delivery

David

[Berlene Herren]

Are you using DNS? If not, then cp /etc/nsswitch.files /etc/nsswitch.conf.

Berlene

[Steven E. Protter]

If the Exchange admin doesn't know what he/she is doing, relay could be openned up for the entire Internet. This is serious.

If you don't have dns enabled as Berlene says, you can do it with /etc/hosts

just add an entry into the file that looks like this.

ip_of_exchange_server hostname_of_exchange_server


save the file.

SEP
35 points to go....