Call forwarding from my outlook account has failed (was working yesterday) -

Louise Taylor 20 Reputation points
2026-06-16T03:01:54.2166667+00:00

Error message: Remote server returned '550 5.7.520 Access denied, Your organization does not allow external forwarding. Please contact your administrator for further assistance. AS(7555)'

I am the only user and administrator, and my user preferences include security admin. I forwarded over 200 emails yesterday and created a rule to send (to another version of my same domain).

How can I get the call forwarding to work again? (I am on a Mac, using the new version of Outlook)

Outlook | Web | Outlook on the web for business | Settings
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Answer accepted by question author

AI answer

2026-06-16T03:02:08.36+00:00

The error means automatic external forwarding has been blocked by your organization’s outbound spam policy, so Outlook on Mac and your rule can no longer forward mail to an external address (even if it’s another mailbox on the same custom domain hosted elsewhere).

Because this is enforced in the service, changing rules or settings in Outlook for Mac will not fix it. The forwarding must be allowed again in the Microsoft 365 outbound spam filter policy.

Since this tenant has only one user and that user is the admin, sign in as the admin and adjust the automatic external forwarding setting:

  1. Open the Microsoft 365 Defender/Exchange admin security settings as an admin.
  2. Locate the outbound spam filter policy (often the default policy).
  3. In that policy, find the Automatic forwarding (or Automatic external forwarding) setting.
  4. Change it from Off – Forwarding is disabled (or a restrictive setting) to either:
    • On – Forwarding is enabled, or
    • A less restrictive option that allows automatic external forwarding for the scenario needed.
  5. Save the policy.

Important details from the policy behavior:

  • When automatic external forwarding is disabled, any Inbox rules or mailbox-level forwarding that send to external addresses are blocked and generate the NDR you’re seeing: 5.7.520 Access denied, Your organization does not allow external forwarding. Please contact your administrator for further assistance. AS(7555).
  • Internal-to-internal forwarding (between mailboxes in the same Microsoft 365 organization) is not affected by this setting.

After updating the outbound spam policy, retry the forwarding rule from Outlook on Mac. New messages that match the rule should start forwarding successfully.

If forwarding is configured at the mailbox level (admin-side) instead of only via an Outlook rule, verify that mailbox forwarding is still set as intended after changing the outbound spam policy.

References:

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