Exchange 2010 Hybrid - On-Premise mailboxes don't receive external domain emails

Copper Contributor

Hi all,

 

I am going into a really weird issue, I have a Exchange 2010 Hybrid scenario, the MX records are pointed to Exchange Online.

 

The issue is that On-premise mailboxes are not receiving email from external domains and the sender doesn't receive any error reply. Mail flow between Office 365 and on-premise is working fine and external domain emails are correctly delivered to Online mailboxes.

 

Does someone have an idea ?

 

Many thanks for your help

 

 

 

3 Replies

Hi Vasil,

 

I have found out that the message were pending within Exchange Online because an insufficient ressource on the On-Premise server. (System was under 5Go space free, after getting some space the messages have been correctly delivered).

 

Many thanks for your help