I have setup an Exchange 2010 Server a couple months ago and it has been working great. Recently (last 2 weeks) we started getting NDR's on some of the email.
... Relaying denied. Please check your mail first or restart your mail session.
Your message wasn't delivered due to a permission or security issue. It may have been rejected by a moderator, the address may only accept e-mail from certain senders, or another restriction may be preventing delivery.
and
Firewall Error
A problem occurred during the delivery of this message to this e-mail address. Try sending this message again. If the problem continues, please contact your helpdesk.
I have not made any changes to the server besides Antispam updates and tweaking the Antispam settings (content filtering actions).
Anyone have any tips of where I could start looking? I was finding information about Receive Connectors possibly being the culprit. I just have the 2 default connectors going. Should I create new ones? If so, how would I create connectors that would suffice for us. (Exchange users and also OWA users.)
I can provide any other details anyone needs in order to help me out.
~Aeotrin
Update: The error I am getting back also looks something like this:
Mail.server.ofRecipient rejected your message to the following e-mail addresses:
Recipient Name ([email protected]) ([email protected])
Mail.server.ofRecipient gave this error: ... Relaying denied. Please check your mail first or restart your mail session.
Your message wasn't delivered due to a permission or security issue. It may have been rejected by a moderator, the address may only accept e-mail from certain senders, or another restriction may be preventing delivery.