Forum Discussion
Best Practice to automatically reject email to invalid recipient?
On a domain I manage, I keep on getting non-delivery messages for an email address which does not exist. These emails are automatically coming from Facebook (which may or may not pay attention t...
You can start by telling us which email system you are using. Exchange will not "catch" such messages by default, so if this is happening with your Office 365 tenant, you have some "catch all" rule set up, or something improperly configured.
The 5.1.4 Hop count exceeded issue is due to possible mail loop, you have to reconfigure the domain as authoritative or fix your connectors. Read here: https://support.office.com/en-gb/article/fix-email-delivery-issues-for-error-code-5-4-6-through-5-4-20-in-office-365-81212ae4-4c36-4e8f-9546-e58b70cfd74b
