>But the timer has to "live" somewhere and to me a form is just as good place for it as any :) And I understand that once the application starts (maybe after server reboots) it runs unattended. Simply connects to the SQL Server every # minutes and - based on some logic - emails or does nothing.

If you go the console app route, you set up Windows Task Scheduler to run it every n minutes.
In essence, Task Scheduler provides your timer.