Sendmail Help

[Daniel Cardani]

I am looking for some sendmail help. I have a server called "ovnoc52" running HPUX11.11 with Oracle and OVO 7.15. This server has two networks connected to it and LAN0 is 10.8.8.8 and LAN1 is 10.0.79.201. LAN0 does not talk to the Big I so I can not use sendmail to send email out via LAN0. LAN1 does not have a default router built on it and can not, but I have a second HPUX 11.11 server called "snooper" and I have static routes build between them. I can send mail out using sendmail from snooper.

What I need is to setup sendmail on ovnoc52 to relay the mail to snooper. Any suggestions. I can not touch the resolv.conf file because OVO uses this for discovery. How can I send mail out from ovnoc52 via snooper.

[Shannon Petry · Accepted solution]

You already answered your own question. You need to use the 2nd machine as a mail hub, which accepts relays from ovnoc52.

Now, here is where you will run into complications.

First, if your spoofing DNS improperly, then you will need to re-establish a system that works. I.E. You have a box doing internal DNS that the ovn... box points at which does not understand internet DNS, and another DNS server that the snoop.. box points at for real lookups.

Routing mail from one system to another is very simple.

Am I correct in guessing that your problem is really DNS?

Regards,
Shannon

[Daniel Cardani]

I am not sure.. How do I tell the ovnoc52 server to relay to snooper. When I run sendmail it does not use relay.

What do I need to edit in sendmail to relay the message to snooper and what do I have to configure in snooper to accept the relay.

[Steven E. Protter]

By default snooper and ovnoc52 will relay each others mail.

All they need to do is have the sendmail daemon running which is also a default.

I suggest as a side note that you keep up with sendmail patches, there are significant security problems with that program.

The machine that wants to relay mail needs this directive in its sendmail.cf


DS
[IP_address_of_relay_machine]


save the file

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


Diagnostic test:

sendmail -v -d8.99 -d38.99 someone@some.net

Type some text



.



This will insure you that mail is routing correctly.

You might not want to leave an HP-UX box configured to relay mail unprotected on the Internet unless you want 100% CPU dedicated to relaying somone elses spam. A firewall of some sort is in order.

Regards and Luck,

SEP

SEP

[Daniel Cardani]

I have the DS defined in my sendmail.cf file on ovnoc52

# "Smart" relay host (may be null)
DS10.13.110.241

When I run sendmail it does not relay the message to 10.13.110.241. I run the sendmail test command and it querys the DNS server on the LAN0 side and not LAN1.

sendmail -v -d8.99 -d38.99 username@somewhere.net


Querying server (# 1) address = 10.8.0.9

Snooper is behind a firewall.

[Daniel Cardani]

Its working now.. Thanks all for your help.

daniel

[Shannon Petry]

Snoop should relay already for the ovnc.. box. I would still look at a few key features that require tweaking at a minimum.
First, you must be a fully qualified internet DNS name to send mail to most of the real world.
Second, make sure your class does re-writing rules so that user@host.domain.com does not go out, but rather user@domain.com.

Then, HP has a great feature. Edit the /etc/rc.config.d/mailsvrs file. Self explanatory from there. After setting the mail server, you need to completely restart sendmail. Use
/sbin/init.d/sendmail stop
/sbin/init.d/sendmail start

Lastly, sendmail if left insecure and under monitored is a time bomb. Get firewall protection first. Then get the Sendmail bible from O'Reilly and Associates. It can be a lifesaver (or company saver if your using sendmail on the internet).

Regards,
Shannon

[Kevin Wright]

simply set the DS macro in ovnoc52 sendmail.cf file to the IP address of snooper

DS

stop and start sendmail, this should be all that's needed.