I have always had trouble with AOL user's registering and/or receiving any e-mail send from my Board, e.g., subscriptions, PM notifications, etc. Up until today, I had been under the assumption that it was a problem on AOL's end and therefore there was nothing I could do to resolve the issue. However, this morning, a tech support worker for my host ISP said the resolution is very simple. He said all that was needed was for me to change the "header" of the e-mail that gets sent out by specifying a "valid from: SMTP address".

Unfortunately, I don't have a clue where to do this; what file(s) are affected, nor what to modify/add.

Can someone help me out with this, please?

in ubbt.inc.php
search for
// MAILER CLASS

edit: the From header is already there....
So I am not sure what your webmaster ment.

Today I read a message about AOL. AOL now does filter smtp port 25. They redirect all traffic over a spamfilter proxy. This cause some trouble exchanging emails with other provider: example "The recipient does not accept mails from 'gmx.de' over foreign mailservers".

Its an AOL Problem. But who need AOL ?