At the risk of beating a dead horse, but you really should consider using SMTP instead if you are really going to be sending a lot of messages.The problem is that doesn't work in more complicated configurations such as when authentication and/or SSL have to happen, not to mention the issue of configuring servers and ports, that users have already configured in their mail clients. Additionally when you use MAPI, messages that you send also end up in your sent items folder. (I also have not had any issue sending lots of messages using MAPI).
Ultimately the utility of vanilla of pure SMTP will depend on customer requirements and how simple the configuration is.
That pretty much sums it up. Also, since everything is done over IMAP with Outlook, I don't really have access to an SMTP server.
Chris -- http://mail.python.org/mailman/listinfo/python-list
