When users sign up for the first time via external database they have always gotten an email with a link to the course along with their user name and password. Now when new people sign up they are still added correctly to the system but they no longer get the intro email. If we send them a message through the internal moodle message system they do get that email, so we are baffled.

If we manually reset their password and send the info they can login and even change their email and get the confirmation email that is required.

It seems email configuration is correct, but perhaps that particular function is outside of the email configuration and uses php mail instead? The problem happened after two things: We moved the server to a new ip address and updated to the latest 2.7.1 version of moodle.

I checked the syncusers.php file that handles the new users and it is the same as before (dated 5/12/14) and the same with cron.php. This leads me to think it might be the movement of the server to an ip that does not have reverse dns which would cause problems potentially with php mail but not with regular mail that goes through our mail server. But it would be strange for moodle to send all other emails properly and only the initial sign-up email differently.