I sent a test message tracking the opening of the emails. I opened the email from 2 of the recipients mailboxes, and the report does not show that any emails were opened.
The HTML source of the email contains the image: http://<myurl>/db/1534/112033/1.gif, where <myurl> is my server's URL. I am able to access this URL in my browser directly, which still does not update the "opened emails" number.
I have the server scheduled to do "incremental update of mailing stats" every 10 minutes, but still not happening.
Is there anything else I should enable or check in my configuration to get this to work?