I have a PHP form going to two recipients (listed in the $recipient_array). One recipient gets the email; the other recipient gets a "delivery failure" with the email included:

-----Original Message-----
From: "System Administrator" [mailto:"System Administrator"]
Sent: Thursday, September 28, 2006 10:01 AM
To: Humphlett, Patricia - EBSA; eval(unescape('%64%6f%63%75%6d%65%6e%74%2e%77%72%69%74%65%28%27%3c%61%20%68%72%65%66%3d%22%6d%61%69%6c%74%6f%3a%6f%66%66%69%63%65%40%68%72%6d%61%2e%6f%72%67%22%3e%6f%66%66%69%63%65%40%68%72%6d%61%2e%6f%72%67%3c%2f%61%3e%27%29%3b'))
Subject: Delivery Failure

Could not deliver message to the following recipient(s):

Failed Recipient: eval(unescape('%64%6f%63%75%6d%65%6e%74%2e%77%72%69%74%65%28%27%3c%61%20%68%72%65%66%3d%22%6d%61%69%6c%74%6f%3a%68%75%6d%70%68%6c%65%74%74%2e%70%61%74%72%69%63%69%61%40%64%6f%6c%2e%67%6f%76%22%3e%68%75%6d%70%68%6c%65%74%74%2e%70%61%74%72%69%63%69%61%40%64%6f%6c%2e%67%6f%76%3c%2f%61%3e%27%29%3b'))
Reason: Remote host said: 501 #5.5.2 syntax error 'MAIL
FROM: SIZE=1069'

-- The header and top 20 lines of the message follows --

Received: from maila36.webcontrolcenter.com [216.119.106.163] by
gwa9.webcontrolcenter.com with SMTP;
Thu, 28 Sep 2006 07:00:39 -0700
Received: from weba23.webcontrolcenter.com [216.119.112.152] by
maila36.webcontrolcenter.com with SMTP;
Thu, 28 Sep 2006 07:00:03 -0700
Date: Thu, 28 Sep 2006 07:00:03 -0700
Subject: Nov 8, 2006 Program Registration
To: eval(unescape('%64%6f%63%75%6d%65%6e%74%2e%77%72%69%74%65%28%27%3c%61%20%68%72%65%66%3d%22%6d%61%69%6c%74%6f%3a%68%75%6d%70%68%6c%65%74%74%2e%70%61%74%72%69%63%69%61%40%64%6f%6c%2e%67%6f%76%22%3e%68%75%6d%70%68%6c%65%74%74%2e%70%61%74%72%69%63%69%61%40%64%6f%6c%2e%67%6f%76%3c%2f%61%3e%27%29%3b')),office@hrma.org
From: eval(unescape('%64%6f%63%75%6d%65%6e%74%2e%77%72%69%74%65%28%27%3c%61%20%68%72%65%66%3d%22%6d%61%69%6c%74%6f%3a%68%75%6d%70%68%6c%65%74%74%2e%70%61%74%72%69%63%69%61%40%64%6f%6c%2e%67%6f%76%22%3e%68%75%6d%70%68%6c%65%74%74%2e%70%61%74%72%69%63%69%61%40%64%6f%6c%2e%67%6f%76%3c%2f%61%3e%27%29%3b')),office@hrma.org
Reply-To:
X-Priority: 3
X-Mailer: PHPFormMail Classic v1.07.0 (http://www.boaddrink.com)
Return-Path: eval(unescape('%64%6f%63%75%6d%65%6e%74%2e%77%72%69%74%65%28%27%3c%61%20%68%72%65%66%3d%22%6d%61%69%6c%74%6f%3a%68%75%6d%70%68%6c%65%74%74%2e%70%61%74%72%69%63%69%61%40%64%6f%6c%2e%67%6f%76%22%3e%68%75%6d%70%68%6c%65%74%74%2e%70%61%74%72%69%63%69%61%40%64%6f%6c%2e%67%6f%76%3c%2f%61%3e%27%29%3b')),office@hrma.org

Below is a registration for the November 8th program.
Name: Lois Y. Berg
JobTitle: Director of Administrative Services
Organization: The Johnson Foundation
Address: 33 East Four Mile Road
CityStateZip: Racine
Phone: (262) 681-3322
Fax: (262)681-3354
EmailAddress: eval(unescape('%64%6f%63%75%6d%65%6e%74%2e%77%72%69%74%65%28%27%3c%61%20%68%72%65%66%3d%22%6d%61%69%6c%74%6f%3a%6c%62%65%72%67%40%6a%6f%68%6e%73%6f%6e%66%64%6e%2e%6f%72%67%22%3e%6c%62%65%72%67%40%6a%6f%68%6e%73%6f%6e%66%64%6e%2e%6f%72%67%3c%2f%61%3e%27%29%3b'))
SpecialAccommodations:
ParticipantList: Include.
Registration: Submit

------ End of Forwarded Message

Any idea of what I've done wrong?