Explanation/Reference:
Explanation:
Microsoft Remote Connectivity Analyzer is a website offered by Microsoft for testing remote connectivity to server services such as Exchange Server, Lync Server and Office 365.
The Office 365 tab on the Remote Connectivity Analyzer has several options for performing different tests regarding Office 365 connectivity. These tests include:
Office 365 General Tests

Microsoft Exchange ActiveSync Connectivity Tests

Microsoft Exchange Web Services Connectivity Tests

Microsoft Office Outlook Connectivity Tests

Internet Email Tests

Mail Flow Configuration

Free/Busy Test

The Office 365 General Tests section includes the following tests:
Office 365 Exchange Domain Server (DNS) Connectivity Test

Office 365 Lync Domain Server (DNS) Connectivity Test

Office 365 Single Sign-OnTest

The description for the Single Sign-OnTest is as follows:
"This test will validate your ability to log on to Office 365 with your on-premises credentials. It also validates some basic Active Directory Federated Services (AD FS) configuration." This test will meet the requirement in this question of verifying that single sign-on functions for the users who access Office 365 from the Internet.