Everytime we reply to someone that is with aol the message gets rejected. If we create a new message and send there is no problem. We are using the new Microsoft Exchange Online as the server and the default outlook client. The error we get for the rejected replies is as follows.... Final-recipient: RFC822; <customer>@aol.com Action: failed Status: 5.7.0 Remote-MTA: dns; mtain-md07.r1000.mx.aol.com X-Supplementary-Info: <mtain-md07.r1000.mx.aol.com #5.7.0 smtp;503 5.7.0 Error: access denied for va3ehsobe006.messaging.microsoft.com[216.32.180.16]>elandwalt

I would open a case with the Exchange Online folks.

AOL is the only ISP in the world that I am aware of that makes new/unknown email systems go through a trial period/pre-approval process. http://postmaster.aol.com/ I would forward this to whomever at Exchange Online you correspond to as they may not have gotten permission from AOL to send email to them (insert comtempt here).