Tag: exchange-online

All the articles with the tag "exchange-online".

• Microsoft 365 Bounce Back 550 5.7.520 Access Denied, Your Organization Does Not Allow External Forwarding

  14 Aug, 2026

  Senders get 550 5.7.520 Access denied bounce backs but the mail actually arrives. The cause is a mailbox forwarding rule colliding with the tenant outbound spam policy. Here is the exact fix.