AOL is rejecting emails from the client’s website, how can I troubleshoot

I am a bit of an email noob. My website is trying to send email from a contact form using the PHP mail function. This works fine when sending it to my Gmail account, but AOL rejects it. I have set up an RDNS record for the client ( fallsroadsunoco.com )

Macintosh:~ TAmoyal$ nslookup 67.23.28.65
Server:     192.168.1.1
Address:    192.168.1.1#53

Non-authoritative answer:
65.28.23.67.in-addr.arpa    name = fallsroadsunoco.com.

Authoritative answers can be found from:

I have even set up an MX record (although I think this is irrelevant because that should only be needed for receiving email). I did some poking around and randomly saw this on my server…but 2 things to note with this output:

1. i changed the receiving email address to blahblahblah@aol.com to keep it anonymous
2. bandop.com was my RDNS host name at the time this email was sent. i changed it to the client's host name fallsroadsunoco.com to see if that would help…and it didn't

sudo more var/spool/postfix/deferred/0/0F902E4F7E
trace_flags=0SO^Lwww-data@comR^Lwww-data@comMN!Received: by bandop.com (Postfix)N5124671id 0F902E4F7E; Sat,ime=1246714223Alog_message_origin=localA
 4 Jul 2009 13:30:23 +0000 (UTC)N+Date: Sat,  4 Jul 2009 13:30:23 +0000 (UTC)N.From: MAILER-DAEMON@com (Mail Delivery System)N,Subject: Undelivered Mail Returned to SenderNTo: www-data@
comNAuto-Submitted: auto-repliedNMIME-Version: 1.0N<Content-Type: multipart/report; report-type=delivery-status;N,  boundary="B68D0E4F7D.1246714223/bandop.com"NContent-Transfer-Enco
ding: 8bitN2Message-Id: <20090704133023.0F902E4F7E@bandop.com>NN$This is a MIME-encapsulated message.NN"--B68D0E4F7D.1246714223/bandop.comN!Content-Description: NotificationN*Content-Ty
pe: text/plain; charset=us-asciiNN+This is the mail system at host bandop.com.NN;I'm sorry to have to inform you that your message could notN<be delivered to one or more recipients. It'
s attached below.NN7For further assistance, please send mail to postmaster.NN9If you do so, please include this problem report. You canN8delete your own text from the attached returned 
message.NN"                   The mail systemNNO<blahblahblah@aol.com>: host mailin-02.mx.aol.com[64.12.137.89] said: 501 SYNTAXND    ERROR IN PARAMETERS OR ARGUMENTS (in reply to MAIL F
ROM command)NN"--B68D0E4F7D.1246714223/bandop.comN$Content-Description: Delivery reportN%Content-Type: message/delivery-statusNNReporting-MTA: dns; bandop.comNX-Postfix-Queue-ID: B68D0E
Status: 5.0.0N%Remote-MTA: dns; mailin-02.mx.aol.comNBDiagnostic-Code: smtp; 501 SYNTAX ERRO(UTC)NN,Final-Recipient: rfc822; blahblahblah@aol.comNAction: failedN
 IN PARAMETERS OR ARGUMENTSNN"--B68D0E4F7D.1246714223/bandop.comN(Content-Description: Undelivered MessageNContent-Type: message/rfc822NContent-Transfer-Encoding: 8bitNN1Received: by ba
ndop.com (Postfix, from userid 33)N5    id B68D0E4F7D; Sat,  4 Jul 2009 13:30:22 +0000 (UTC)NTo: blahblahblah@aol.comN!Subject: Your contact form works!N$Date: Sat, 4 Jul 2009 09:30:22 -
X-Priority: 3N?X-Mailer: PHPMailer (phpmailer.sourceforge.net) [version 2.0.4]NMIME-Version: 1.0NContent-Transfer-Enallsroadsunoco.com>N
oding: 8bitN)Content-Type: text/plain; charset="UTF-8"NNName: Tony AmoyalN
encoding=8bitE03@gmail.comMessage:NCan you see this?NNN$--B68D0E4F7D.1246714223/bandop.com--XA

Any idea why only AOL would be rejecting my messages? Also note that they are not making it to the SPAM folder.