You have a hybrid deployment of Exchange Server 2013 and Office 365.
The mail flow between Office 365 and the on-premises Exchange Server environment is routed
through an Exchange Server 2010 Edge Transport server.
Your company is assigned a new set of public IP addresses.
A network administrator updates the external firewall address and all of the associated DNS records.
Office 365 users report that they cannot receive email messages from on-premises users.
You discover that outgoing email messages to Office 365 are in the Office 365 SMTP queue on an
Edge server.
You need to ensure that the on-premises users can send email messages successfully to the Office
365 users.
Which tool should you use?

A.
The Exchange Management Console

B.
The Exchange Control Panel in Office 365

C.
The Exchange Admin Center

D.
The Exchange Remote Connectivity Analyzer

Explanation:
Note:
* The section describes the user interface elements that are common across the EAC (Exchange
Admin Center).

* Check the mail flow setting.

Managing Directory Based Edge Blocking (DBEB) feature in Exchange Online Protection (EOP)