5.7.1: The sender is not authorized to send e-mail messages to this e-mail address. Possible causes: 1)The session is not authenticated and does not have the 'ms-Exch-SMTP-Submit' permission. 2)The session is authenticated but does not have the 'ms-Exch-SMTP-Submit' permission. 3)The 'MAIL FROM' command specified an address at an authoritative domain and the session does not have the 'ms-Exch-SMTP-Accept-Authoritative-Domain-Sender' permission. 4)The authenticated user does not have permission to submit on behalf of the sender address specified in the header of the message and the session does not have the 'ms-Exch-SMTP-Accept-Any-Sender' permission. 5)The recipient domain does not match any of the accepted domains and the session does not have the 'ms-Exch-SMTP-Accept-Any-Recipient' permission. 6)The recipient domain is rejecting all mail from this server using a block list.
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