How many times in your profesisonal life does a problem just go away?
Never. Computers don't fix themselves. What *might* have been happening is that the SMTP server that you are mailing through was spooling the email for some reason and then it eventually was sent. This would give the effect of the mail only being sent after the user logged off as you would have to log off then go check your email, etc.
However, as Peter pointed out, if the code is executed and there are no errors, that email will be sent.
Glad everything is working for you.
Read this if you want to know how to get a correct reply for your question:
^^Took that from planoie's profile^^
^^Modified text taken from gbianchi profile^^
Technical Editor for: Professional Search Engine Optimization with ASP.NET
Why can't Programmers, program??