On one of my client sites they have a Telstra Internet connection. An Exchange server sits on the network and forwards mail out to the Telstra Smarthost smtp.telstrabusiness.com.

After an update to a Dansguardian proxy server and the subsequent failure of clamd to launch (due to the update changing the permissions of /var/lib/clamav) Dansguardian went on an email sending spree of a couple of thousand emails in roughly an hour. The smart host rightly felt it was being shouted at so put a hand in it's face and said nuh uh ahh.

To test I tried to telnet to smtp.telstrabusiness.com port 25 I got:

"421 nskntcmgw05p BigPond Outbound Connection refused. OB112"

So the remote end hated me.

I knew it wasn't internet or routing because I ccould telnet to port 25 on mail.bigpond.com and mail.pm.telstra.com and it worked fine…

So I rang Telstra Internet Direct

As is typical with any helpline the frustration is:

1. You aren't really sure you are ringing the right place.
2. The automated phone script says to hang up and reboot the modem. Unhelpful and not going to fix the problem.
3. In defence of the human that you finally talk to after suffering the phone script. The person you get really is trying valiantly to help you but...
   1. Doesn't know what a smarthost is so doesn't understand your problem, or the explanation of the problem
   2. Wants to remote in to check settings assuming you are on a computer running Outlook and their Business Mail offering.

After a while I was glad to tell them the problem has self cleared and I'm again getting a connection

"220 nskntcmgw05p BigPond Outbound ESMTP server ready"

I've found if the problem isn't self clearing it takes an almost superhuman level of patience to get them to the point where they will escalate to 2^nd or 3^rd level support. Once you have the back room guys or girls engaged and you are talking their language the problem get's resolved really quickly (they know their stuff). You just need to go through the "Welcome to the Internet Help Desk" scenario first.