Thanks for that, we found out what the problem was using your help. Apparently access permissions were not set correctly on the PEAR directory.
Now that we are succesfully sending via PEAR, we are having problems sending to a BCC address.
Ive found a couple of others with the problem on the forum but it seems to be unresolved.
Ive tried to throw together a solution (using limited php knowledge and even less knowledge of how your code works) to hard code in my desired bcc address into the $to variable like so
mail is sent to the $bcc address but it is shown in the recipients list i.e. it is not really a blind copy.
line 4277 of formmail.php
$bcc = "firstname.lastname@example.org";
$to = $to.", ".$bcc;
Does this mean it has somehow got into $a_headers?