Hi peeps,

I cannot expose this issue in my local enviroment, here on dnn.com or on two other sites that have forums installed.  This really leads me to believe there are some configuration errors.  Please see the user docs but also:

1. Make sure you have a proper from address in the configuration

2. Make sure show sender address is NOT checked.

3. Obviously, make sure host settings are allowing sends via smtp. 

4. Make sure all email addresses receiving notification are correct.

I have added error trapping which should allow emails to go out even when there are bad addresses.

There have been only two peeps that had this problem, so it seems.  I really think this is in your portal or module configuration.