I have a strange problem. We are using EE2.5.3 and Discussion Forum3.1.9. I also have Forum Subscribe2.3.2 installed. On our forums, if someone enters a new reply to a topic which has several people subscribed, the module will send an email only to the last person who replied to that thread. I have tested by changing the email protocol and uninstalling Forum Subscribe. I am currently using SMTP as the email protocol.
Any help or other ways to troubleshoot would be appreciated.
Edit: After further trouble shooting, it appears that the issue is with the thread subscription mechanism in EE. If a new thread is started, everyone subscribed to that forum with Forum Subscribe receives an email as they should. However, if all of those people then subscribe to the thread in EE, when anyone responds, the response only goes to the last person that responded (if they have left selected the "Notify me via email..." checkbox). Any ideas?