We are getting an email undeliverable message sending to a specific user. We are also having issues receiving email only from a couple of domains.
The error code the the undeliverable email was 5.7.1. I have found the error detail but could do with some assistance in resolving it.
We are using SBS2011 on a Single Server with Sophos installed on both client and server for mail scanning. I don't believe its a virus/spam as we can send to other domains.
Any help would be greatly appreciated.
5.7.1: The sender isn't authorized to send e-mail messages to this e-mail address. The possible reasons for this are: 1)The session isn't authenticated and doesn't have the 'ms-Exch-SMTP-Submit' permission. 2)The session is authenticated but doesn't have the 'ms-Exch-SMTP-Submit' permission. 3)The 'MAIL FROM' command specified an address in an authoritative domain but the session doesn't have the 'ms-Exch-SMTP-Accept-Authoritative-Domain-Sender' permission. 4)The authenticated user doesn't have permission to submit on behalf of the sender address specified in the header of the message and the session doesn't have the 'ms-Exch-SMTP-Accept-Any-Sender' permission. 5)The recipient domain doesn't match any of the accepted domains and the session doesn't have the 'ms-Exch-SMTP-Accept-Any-Recipient' permission. 6)The recipient domain is rejecting all mail from this server using a block list
In the email bounce back there was this
LLAR.NET.UNIOVI.ES #530 5.7.1 Probable spam source: hostMY IP ADDRESS.in-addr.btopenworld.com: