Error : 550 5.7.51 TenantInboundAttribution in Email Security Cloud

Products

• Email Security.cloud

Issue/Introduction

Track and Trace displays an error message "550 5.7.51 TenantInboundAttribution; There is a partner connector configured that matched the message's recipient domain. The connector had either the RestrictDomainsToIPAddresses or RestrictDomainsToCertificate set

Environment

Email Security.cloud

Cause

The Track and Trace logs shows an error stating "550 5.7.51 TenantInboundAttribution; There is a partner connector configured that matched the message's recipient domain. The connector had either the RestrictDomainsToIPAddresses or RestrictDomainsToCertificate set

This is Microsoft rejection error code.

Resolution

• This error indicates that the recipient domain has a connector set up to restrict senders by IPs or Certificates, or the sending organization has set up a connector with the recipient's organization or vice versa.
• The recipient's custom domain should be specified in the connector so only messages sent to their custom domain could be routed.
• Please contact the recipient's admin to check the connectors and adjust them as necessary to allow email messages to be delivered from the sending domain.