Directory-Based Edge Blocking (DBEB) and public folders in Exchange Online

Question

According to the article below, it if you switch your domain to "Authoritative relay", it is not possible to use mail-enabled public folders that are hosted in Exchange Online, because Directory-Based Edge Blocking (DBEB) doesn't support it. Is there any workaround for this, to use mail-enabled public folders that are hosted in Exchange Online, even the domain is set to "Authoritative relay"?

https://learn.microsoft.com/en-us/exchange/mail-flow-best-practices/use-directory-based-edge-blocking

Answer 1

You can use them, you simply wont be able to receive messages from external addresses. And no, no workarounds. DBEB does not support MEPF objects, their corresponding addresses are never synchronized, so any external messages addressed to them will be blocked.

If you have on-premises MEPF, then you can use the AAD Connect's feature that enables support for DBEB, as detailed here: https://techcommunity.microsoft.com/t5/exchange-team-blog/office-365-directory-based-edge-blocking-support-for-on-premises/ba-p/606740

But that only applies to on-premises MEPF.