Check which ports are open to the outside world. Helps make sure that your firewall rules are working as intended.
One of a set of tools we are providing to everyone as a way of saying thank you for being a part of the community.
|Office 365: Is there a way to prevent emails from being forwarded with Outlook Rules?||9||24|
|Exchange 2013 received lots of bounceback email from external mail server||1||25|
|Exchange Online Retention Policy||2||20|