Email forwarding to Reamaze not working

If Microsoft 365 or Outlook is already configured, the remaining Microsoft-side checks are these:

1. Verify the outbound spam policy allows external forwarding.
   • In Microsoft 365, automatic external forwarding can be blocked by the outbound spam filter policy.
   • If it is set to Off - Forwarding is disabled, forwarding to an external service will fail and generate a nondelivery report.
   • Avoid Automatic - System-controlled because its behavior can differ by organization. Use On - Forwarding is enabled or Off - Forwarding is disabled explicitly.
2. Confirm whether mailbox forwarding is enabled in addition to an Inbox rule.
   • If mailbox forwarding is enabled on the mailbox, Inbox rules that redirect messages will not work by design.
   • In Exchange Online PowerShell, check:

          Get-Mailbox <user ID> | FL ForwardingAddress,ForwardingSmtpAddress,DeliverToMailboxAndForward
     

   • If a forwarding address is set and DeliverToMailboxAndForward is True, disable mailbox forwarding if the goal is to use an Inbox redirect rule:

          Set-Mailbox <user ID> -DeliverToMailboxAndForward $False
     

3. Check whether the target domain is treated as a remote domain with automatic forwarding disabled.
   • In Exchange Online PowerShell, check:

          Get-RemoteDomain | Where {$_.AutoForwardEnabled -eq $False}
     

   • If the destination domain matches one of those domains, Inbox rules that redirect messages will not work by design.
4. If forwarding is configured from the mailbox settings instead of a rule, verify the mailbox still has a license.
   • In Microsoft 365 admin center: Users > Active users > select user > Mail > Manage email forwarding.
   • If the option is missing, a license must be assigned to the user account.
   • Do not remove the user license or delete the account, or forwarding stops.
5. If this is Outlook.com rather than Microsoft 365 business mail, recheck the mailbox for hidden forwarding or rules.
   • In Outlook.com, review Settings > Mail > Forwarding and Settings > Mail > Rules.
   • Also check whether mail is being diverted by Junk Email settings or blocked sender entries.
6. Run a controlled test and inspect the result.
   • Send a test message from another account to the affected mailbox.
   • If a bounce or nondelivery report is returned, that points to external forwarding being blocked.
   • If no bounce is returned, check whether a rule is moving mail elsewhere instead of forwarding it.

Important behavior to account for:

• Disabling automatic forwarding in the outbound spam policy disables both user Inbox rules and admin mailbox forwarding to external addresses.
• Internal forwarding between users is not affected by that setting.
• If a rule forwards or redirects to multiple individual recipients, Exchange Online has a limit of 10 recipients.

• Control automatic external email forwarding from cloud mailboxes
• Diagnose Outlook Inbox rules that aren't working
• Configure email forwarding in Microsoft 365
• Can't send or receive email in Outlook.com
• Not Receiving Emails - Microsoft Q&A