OK, so the forum is currently plagued by a "mail error" message during posting / replying.
The ONLY problem at the moment is with the E-MAIL function. The problem that is arising though is that when people are subscribed to a particular forum (that is, they have set up their account to send e-mail notifications when new posts are made in it) it displays an error message for people (because the e-mail function which would usually send these notification messages is
not workingEXAMPLE: Rod* has subscribed to the chit-chat forum. So the forum tries to send him an e-mail notification when I submit this post, but the e-mail function isn't working so the error message is displayed.
*[i]name changed for anonymity and reasons of personal safety[ /i]
THEREFORE:
Please un-subscribe yourself from any topics or forums you have subscribed to. To do this, go to MY CONTROLS, and click on the items ringed in the picture below. After this just put checkboxes in any forums/topics present and click UNSUBSCRIBE.

Unfortunately, I don't think as an admin I can unsubscribe everyone from every topic at once ... would make life a lot easier.
In the meantime, while I continue to try to fix the problem, you can always use the "active topics" feature which will tell you where new posts have been made. Full information on this feature
HERE.