As many of you know, I am a big fan of the guys working on the ACE Toolkit. I can't count the number of hours these fine people have saved me over the past six years, on countless projects. The reliability of their software has never ceased to amaze me. As such, I've used their components to construct a set of SMTP and POP3 mail components that you are free to use in your C++ projects. Granted, these components are very primitive, and really don't use the functionality given us by ACE, but the components are in an evolving state and have a simple interface that is not particularly liable to change. If anything new interfaces will be coming along that will improve on this base I've created, hopefully proving to be more robust and error-resistant.
In the extensive testing I've done with these components, they tend to fail in reliable ways on communication errors, and have yet to cause lost mail due to timing/timeout errors. Operator error is always a risk however, so caveat emptor...
Q: Is MonitorService for me?
That depends. If your software has the following "features":
then MonitorService is for you.