Exim4 outbound issue

[brokenhalo]

Hello guys. I am having an issue that is completely driving me nuts. I have had sendmail working perfectly on this server for over 3 years. I use it only for outbound mail to send out the contents of a web form and internal server alerts (forwarding root's mail via /etc/aliases). I had some unrelated issues last weekend and rebooted the server - now mail will not send to any outbound address (internal mail seems to be working).

I uninstalled sendmail and installed Exim4 (which I've been wanting to do anyways) hoping the change in MTA and default configuration would help, but it didn't. FYI: I setup exim using dpkg-reconfigure exim4-config and choosing "Internet site" and mainly defaults.

/var/log/exim4/mainlog is giving me the following issues...

1REwQ8-0006QU-7H == some@email.com R=dnslookup T=remote_smtp defer (-53): retry time not reached for any host

After an amount of time, message will eventually fail with...

1REwQ8-0006QU-7H == some@email.com R=dnslookup T=remote_smtp defer (110): Connection timed out

I am able to telnet to the remote server above (email.com) and send a test message as well as receive the test message...

telnet mail.email.com 25
Trying **.**.**.**...
Connected to mail.email.com.
Escape character is '^]'.
220 mail.email.com ESMTP Exim 4.67 Sat, 15 Oct 2011 01:14:51 -0400
ehlo my.server.org
250-mail.email.com Hello my.server.org [**.**.**.**]
250-SIZE 31457280
250-PIPELINING
250-AUTH PLAIN LOGIN
250-STARTTLS
250 HELP
mail from: root@my.server.org
250 OK
rcpt to: some@email.com
250 Accepted
data
354 Enter message, ending with "." on a line by itself
Test Message
.
250 OK id=1REwbi-0007Sf-Jd
quit
221 mail.email.com closing connection
Connection closed by foreign host.

There has to be something simple I am missing. Any help is greatly appreciated.

Brad L.
Systems Engineer
Prestige Technologies
bradlaszlo[at]prestigetech.com

http://www.prestigetech.com

"Some things Man was never meant to know. For everything else, there's Google.

 

[Noway2]

I believe the error message is saying that your outbound message attempt received a temporary reject code. (smtp-remote defer, meaning message deferred due to response of remote smtp server).

If you search on that error message, you will find a lot of different causes ranging from corrupted exim databases, to greylisting, and firewall (outbound) ports being closed.

Your telnet tests of the remote host indicate that it is working and is capable of receiving. It also says that you are sending to a valid recipient. This suggests that there is something wrong on the sender domain.

My advice would be to look in the logs, or even increase the debug level of the logs if you can for additional information that might show the cause of the rejection. Failing that, you might want to look at the transaction with a packet analyzer to see where in the transaction the failure is occurring and why.

 

[brokenhalo]

Thanks! That is exactly what that error means. I have done several Google searches for that error and came across likely the same exact searches you did.

I do not believe the issue to be a corrupt Exim DB. I have completely uninstalled and reinstalled Exim in an ettempt to resolve this issue with the same result (I've even tried installing Postfix and plain ol' Sendmail).

I know also it's not a greylist or blacklist issue because I am sending test emails to a server that is wide-open and does not check any sort of lists. Again, this server was able to send basic alert emails perfectly up until I rebooted it.

Obviously the ports aren't closed because I am able to Telnet and sent test messages through port 25 with no issues. There is something very simple that I am missing, I know it. I will increase the debug level and see what else I find. Anyone else have some insight?

Brad L.
Systems Engineer
Prestige Technologies
bradlaszlo[at]prestigetech.com

http://www.prestigetech.com

"Some things Man was never meant to know. For everything else, there's Google.

 

[brokenhalo]

Well, I feel stupid. CSF+LFD has an "SMTP_BLOCK" option that I had set to 1 (disable SMTP). This was strange because I was able to send mail through port 25 using telnet no problem. I won't overlook that option again. Thanks as always for your help!

Brad L.
Systems Engineer
Prestige Technologies

http://www.prestigetech.com

"Some things Man was never meant to know. For everything else, there's Google.