Helo Error - Not Acepting Remote Emails

domain1.com has two servers:

#Server PHP - hosts php and handles apache/mysql requests.
#Server 2 - handles mail and dns requests.

Yesterday we moved mail from # server 2 to a new mail server, a cPanel one, all mailboxes are created, users can send and recieve email using webmail, mail clients, etc.

But.. while trying to send mails using PHP authenticated from the #Server PHP/Apache/MySQL , we got this error from the mail servers:

Code:
We do not authorize the use of this system to transport unsolicited, 220 and/or bulk e-mail. SMTP -> FROM SERVER: SMTP -> FROM SERVER: SMTP -> ERROR: HELO not accepted from server: SMTP -> get_lines(): $data was "" SMTP -> get_lines(): $str is "220-srv247.serverhost.com
This was working when mails were recieved/sent in Sendmail (an Ensim box), now with Exim 4.x on a cPanel box we got this issue.

Already added IP address from #server php into all Exim whitelists, also added the IP to /etc/alwaysrely, but didn't help.

Im using RHE 5.2 on the mail server and latest Release build.