FormMail valid recipient

[Anon]

I am receiving the following error upon SUBMIT:

I NEED VALID RECIPIENT EMAIL ADDRESS () TO CONTINUE

The following line is in the form:

<input type=hidden name="recipient" value="[e-mail]">
[e-mail] is a valid email address, used to send and receive
all the time.

In the FormMail.php file on the server, both $Referers and $Banlist are
empty (i.e.., () )

Any ideas?

Eric