Microsoft Connectivity Analyzer (MCA)
The Microsoft Connectivity Analyzer (MCA) is a diagnostics tool for troubleshooting and testing connectivity to several Microsoft messaging products from a client machine on an organization's network.
MCA checks common connectivity symptoms from a local Windows machine behind an organization's firewall by replicating different logon and mail flow processes. MCA stores results in a Hypertext Markup Language (HTML) file that team members in an IT department can share to troubleshoot an issue. MCA supports connection tests for Outlook, Office 365 and Skype for Business.
Microsoft Connectivity Analyzer tests and features
MCA runs diagnostic tests for several scenarios:
- "I can't log on with Office Outlook."
- "I can't send or receive email on my mobile device."
- "I can't log on to Lync on my mobile device or the Lync Windows Store App."
- "I can't send or receive email from Outlook (Office 365 only)."
- "I can't view free/busy information of another user."
- "I am experiencing other problems with Outlook (English Only)."
- "I can't set up Federation with Office 365, Azure or other services that use Azure Active Directory."
Desktop tool attempts to diagnose
Outlook connectivity problems.
For example, an enterprise that uses Exchange Online as its messaging platform would run the "I can't send or receive email from Outlook (Office 365 only)" test for users with email problems in Outlook. For this issue, MCA checks both inbound and outbound Simple Mail Transfer Protocol (SMTP) mail flow and tests connectivity to the domain and Office 365 servers.
Microsoft released version 1.0 of MCA in February 2013 with tests for the first five scenarios, adding two additional tests in subsequent versions. Microsoft released the latest version, 2.6, in October 2014.

Microsoft Connectivity Analyzer vs. Microsoft Remote Connectivity Analyzer
Microsoft provides a similar diagnostic tool called Microsoft Remote Connectivity Analyzer.
Microsoft Remote Connectivity Analyzer -- originally released as Exchange Server Remote Connectivity Analyzer -- is a more comprehensive collection of connectivity testing tools. The main difference is the Remote Connectivity Analyzer runs outside the organization's firewall from a Microsoft web-based application. The Remote Connectivity Analyzer also presents its troubleshooting options in a tabbed menu layout rather than a wizard interface.
The Remote Connectivity Analyzer tests various functions unavailable in the Microsoft Connectivity Analyzer, such as checking that the correct server ports respond to outside queries and remote access authorization works as expected.