Relay Access Denied
Another domain error that can be due to either the sender's or recipient's domain is a relay access denied error:
<firstname.lastname@example.org> host wormwood.Pen Publishing.com said:
554 <email@example.com>: Recipient Address rejected:
Relay access denied
This error indicates that, somehow, a message intended for a Yahoo.com address found its way to our penpublishing.com mail server, and since our server doesn't accept mail for yahoo.com, the message was rejected. It is quite rare, actually, to reach a completely incorrect mail server when sending email to a domain, so if you receive this message, the problem is usually a misconfiguration error with the receiving domain (for example, if you receive notice that mail sent to a Pen Publishing user was rejected by a Pen Publishing mail server with this "Recipient Address rejected," error, this could indicate a problem with our mail servers, since Pen Publishing's mail servers obviously should accept email for Pen Publishing users. Or, it could indicate a problem where the sender's system isn't looking the mail server up correctly).
Another reason for receiving this error is the possiblity that a domain has recently changed hosts, and while the change has taken place, the new domain record has not yet propagated fully, and your message reached the old hosting company which no longer accepts mail for the leaving domain. If you receive this error, try resending your message twenty-four hours later.
Another Relay Access Denied error exists: "Sender Address rejected: Relay Access Denied"; this is actually an anti-spam bounce, so please see Relay Access Denied: Anti-Spam bounce below.