Very useful and clear reference Greg, nicely illustrated too, I hope the guys think it's worthy of inclusion in next year's 'Best of' publication - I can never find this information when I need it. 

One thing I'd like to point out as a useful addition to it is an article that Microsoft published at : http://support.microsoft.com/kb/311231/EN-US/

Point Q7 is worth reading, as it recommends that you only connect to a POP3 server on your local network, because using a server hosted by an ISP may prove unreliable and cause SQLMail to hang, which requires a restart of SQL Server if you want to send mail again.

I am looking for this solution actually, our sqlmail hang everytime after exchange server reboot... your article helps. thanks.

I have used POP3 and SMTP to send SQL Mail for some years. But I succeed little since the ISP's mail server regard our SQL Mails as junk mails to block off. That dismay me.

Now inside company I use Microsoft Windows Server 2003 , the system contain a simple POP3 and SMTP service.

Bob Xu from China. ^_^

I have 2 instances of SQL running on my server. One of the instances have set the Mail alert and it is working perferct. The other instance don't pass the operator test.

 I need to have diferents mail profiles, for more of one instance???

I tested using the same profile or with a second profile set EXACT as the other but don't pass the operator test.

Thanks in advance!!