Office 365 Outlook email issue
Microsoft put out a message that email forwarding to external domains will be turned off by default. The email forward will get a bounceback of:
“Remote Server returned ‘550 5.7.520 Access denied, Your organization does not allow external forwarding.”

Office 365 now blocks all auto-forwarding by default or they have set their own custom blocking.

If you would like email forwarding enable for your organisation you can edit the policy show here:

Open Threat Management and select Policy

Open Anti-Spam then select Edit Policy

Select Automatic Forwarding drop down menu and select On – Forwarding is enabled

Allow a few hours for policy to populate.