Sharepoint 2010 - Email alert failure
Well, I forgot that rule and was going nuts trying to figure out why my Sharepoint 2010 alerts were no longer working after I upgraded from Sharepoint 2007.
When I created the alerts, I was getting the confirmation email, but the alerts were not working.
I have two servers, a SQL server and a web front end. My SQL server has reporting services installed but not integrated with sharepoint since that was giving me problems (more on that in the future).
I double and triple checked the timer jobs on the two servers that I had and everything looked fine. I ran all the scripts in Powershell to make sure that the hostname of my sharepoint web front end was changed on the migrated alerts, and I found that even new alerts didn't work.
Turn out my problem was that Exchange was set to allow SMTP from my web front end, but not the SQL server. During installation, the installer told me I needed to install Sharepoint on the SQL server even though at Techmentor and the Sharepoint 2011 conference the speakers said not to.
So the first time I created an alert from SQL Reporting services on my database server, Reporting services was nice enough to give me a clear error message right on the webpage.
I needed to add my SQL server to the Exchange Server so it would be allowed to send out emails!
It looks like the alert confirmation comes out of the web front end and the alerts themselves come from the backed, in my case the SQL server.
Solution: Make sure your Exchange server is allowing all your sharepoint servers to send emails!