If you’re an Exchange Online or Exchange Online Protection (EOP) subscriber and you have configured connectors, this post contains important information that might impact your organization. To make sure that your mail flow isn’t interrupted, we strongly recommend that you read this post and take any necessary action at your earliest convenience.
Read more at source: https://blogs.technet.microsoft.com/exchange/2016/03/29/important-notice-for-office-365-email-customers-who-have-configured-connectors/
