Our college recently changed our students email addresses to include the year of entrance. For example, the old address was smithj@ and the new ones are smith.17@. (Not my idea.) Most Moodle mail seems to work fine, such as assignment submissions. But Forum announcements only go to students without the .17 in the name. There are no errors in can find on the server. But we do not use the PHP mailer, we use an direct connection to Exchange. There are not any errors on the Exchange server. Now, that we know about the problem we can work around it, but we need to come up with a solution before the next group of students come in.