BARRACUDA NETWORKS ESS INTERNAL MAIL ROUTING – RELOADED

When my customer was trying to email an external domain, they would receive an NDR with the error below. Inbound messages from that domain were being received by my customer without an issue. 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 Say What? If …