After I upgraded the kernel (http://blog.linode.com/2009/08/17/new-k ... abilities/), I started having problems with the email accounts hosted on my Linode. I still haven't been able to determine the cause. My setup is based on the instructions at: http://workaround.org/articles/ispmail-etch/

The first problem that I noticed was that emails would send but never be received. Looking at the log, I saw that outgoing emails were being delayed. I couldn't determine the cause, but restarting the virus scanner by running "/etc/init.d/amavis restart" fixed this. Almost everything appears to be back to normal. The last problem that I have noticed is that sending from SquirrelMail to email addresses hosted elsewhere results in the message "Transaction failed 554 5.7.1 <user@example.com>: Relay access denied". Sending from my normal mail program works. I didn't change anything in my setup, and can't see anything wrong with my configuration. Any ideas why a reboot would cause these problems and how to fix them? I've spent hours on this, and can't find anything wrong.

Thanks![/code]

I don't know what the solutions to your problems are, but they don't have anything to do with the kernel update. I think it's likely that configuration changes were made some time ago but not applied, and they were applied on the reboot.

That sounds reasonable. I wouldn't expect it to have anything to do with changing a kernel, but I also don't think I changed anything after the last time the mail server was restarted. I can't see any reason I would have had to manually restart AMaViS after rebooting. Now that it is working, I still can't see any reason why SquirrelMail won't send to other domains.

You'll need to tell us what MTA you're using and some more info (I'm not reading that tutorial).

Guessing that you're using Postfix, please post the output of

postconf -n

Also post the FULL log line that says "relay access denied" and a couple before & after it. We need to determine who is denying you: your server or the remote.

I'm guessing your "mynetworks" setting is now incorrect, or that you've lost "permit_mynetworks" in any of the smtpd_*_restrictions lines. Again, assuming Postfix.

Aha! Yes, I'm using postfix. I'm new to email admin, so I didn't notice the missing "permit_mynetworks". I added that, and everything is working the way I want it to. Thanks!

Just be careful you're not making yourself into an open relay. If you want more eyes on your config to help check, post the output of postconf -n.