Had one of those ‘how weird’ moments today. We seemed to not be sending emails from a web site I look after. We’re using SQL Server 2008, and the terrifically handy Database Mail service.

I originally set this up, using instructions I found in a well explained blog post ‘Installing and Configuring Windows Server 2008 SMTP‘.

When I checked the Database Mail logs I found a bunch of errors saying:

The mail could not be sent to the recipients because of the mail server failure. (Sending Mail using Account 1 (2011-03-25T18:13:13). Exception Message: Could not connect to mail server. (No connection could be made because the target machine actively refused it 127.0.0.1:25).

Which seemed odd. So I tried a simple Telnet localhost 25, and received connection refused. Which made me wonder where the SMTP service had gone.

I checked the Features list in Server Manager, and the SMTP service was showing – so I definitely wasn’t hallucinating that I had originally installed the service (it’s not installed by default).

I tried sending a Test Mail (right click on Database Mail in SQL Server Management Studio, then used the following to check the send log and the error log:

SELECT * FROM msdb.dbo.sysmail_allitems WHERE mailitem_id = [test mail id]

SELECT * FROM msdb.dbo.sysmail_event_log WHERE mailitem_id = [test mail id]

And it showed as failed, with the same error message I’d been seeing in the logs. Then I opened IIS6.0 – the SMTP service was not showing.

Checking the logs showed the emails starting to error on a specific day. Which makes me wonder whether someone else on the team has been messing around the on the server.

I decided to try and reinstall, so I used Remove Feature in Server Manager to remove the SMTP service, then Add Feature to reinstall, and then again followed the instructions in the above blog post – which is really just about ensuring you’ve set Relaying for the localhost, so the SMTP service will accept emails from the SQL Database Mail service.

A test email went through fine. And trying functions on the web application showed emails sending fine as well.

So I have a little bit of a mystery. SQL Database Mail was all fully installed and operational. But the SMTP service seemed to have disappeared, or somehow been changed. Think I had better ask around to see who has been doing what.