can't email out of HP-UX server

[Debbie Fleith]

Can anyone point me in the right direction for an issue where we can sendmail to recipients setup locally, but can't send mail out of the local server. This system recently had a change to the DNS addresses, but DNS appears to work with other services like ftp, nslookup, etc.

I'm getting mail returned to root's mailbox with these errors, no matter what domain I'm trying to mail to outside.

Deferred: Connection timed out with mail1.gbg.com.
Warning: message still undelivered after 4 hours
Will keep trying until message is 5 days old

[spex]

Debbie,

Your server can't reach your mail relay. Make sure that 'mail1.gbg.com' resolves to an IP address:

# ping mail1.gbg.com

If get 'ping: unknown host ', check your DNS settings and/or add 'mail1.gbg.com' to /etc/hosts.

PCS

[Debbie Fleith]

vhonick 21> ping mail1.gbg.com
PING mail1.gbg.com: 64 byte packets
I can't ping mail1.gbg.com, but I can resolve to an ip address with nslookup (see below). Does that make sense? Adding all the email servers to /etc/hosts isn't a solution for me (I won't know them all)

ping mail1.gbg.com:
----mail1.gbg.com PING Statistics----
11 packets transmitted, 0 packets received, 100% packet loss

==============
nslookup mail1.gbg.com:

looking up FILES
Trying DNS
Non-authoritative answer:
Name: mail1.gbg.com
Address: 216.16.239.150

[Sandman!]

Maybe a firewall is blocking that port which prevents you from sending outgoing mail. Check with the security team and ask them if they can unblock that port.

~cheers

[spex]

Debbie,

Can you telnet to port 25 and send a message manually?

# telnet mail1.gbg.com 25
...
HELO gbg.com
MAIL FROM: root
RCPT TO:
DATA

.
quit

You said you made DNS changes, did you stop/start the sendmail daemon afterwards? Has your server's IP address changed? If so, was your mail relay's configuration updated?

PCS

[Debbie Fleith]

I have restarted sendmail, and the IP of this HP-UX server did not change.

I cannot telnet to port 25, so I will look into the firewall settings.

[Marvin Strong]

I would start by doing an nslookup on the hostname and IP, make sure you can resolve both. for mail1.gbg.com

Then try to ping name, FQDN, and IP of mail1.gbg.com, ICMP could be disabled though so that may not work.

You could then try traceroute to the mail server. Of course it might also be blocked.

You could also try to telnet to port 25 on mail1.gbg.com to make sure that its accepting mail.

Not sure what DNS changes you made, but if /etc/resolv.conf was changed make sure it has the correct permissions.