556 Requested action not taken: domain does not accept mail Recipient address has null MX

Reason

The email could not be delivered because the recipient domain is using the "Null MX" - No Service MX Resource Record - via DNS to indicate that it will not accept any email.

Solution

The owner of the domain must publish an MX record in the DNS that allows emails to be accepted.

For more information, see the RFCs at the following links:



See also: General information on our error messages.