A client recently switched to Exchange Server / Outlook for their email. Since then emails from my company to any email address at their company bounce back from the System Administrator with this error:
Your message did not reach some or all of the intended recipients. Subject: Email Solution Sent: 12/12/2012 11:08 AM The following recipient(s) cannot be reached: 'firstname.lastname@example.org' on 12/12/2012 11:08 AM 550 5.1.1 <email@example.com> recipient rejected
Looking in the Message Options of the bounce back email shows no data in the Internet Header field.
My client's IT guy says we're not being blocked, but I cant think of any other reason the bounce would occur.
Any suggestions on what questions to ask or how to fix this would be helpful.
I'm using a desktop version of Outlook 2007 and connecting through my ISP.