Office 365: Can’t open Outlook, part 4; MX Records and Ms Remote Connectivity Analyzer

Check the MX record configuration
MX stands for “Mail Exchanger” and is one specific type of DNS record used by the DNS server to determine the server responsible to receive the email messages.
The MX parameters are used by the DNS to prioritize mail distribution if multiple mail servers are available.
It might be the case to check the MX records configuration.
Start the DOS Command Prompt. Click on Start. Type “cmd” > click on it once displayed by Windows.

Type "nslookup".
Your client’s DNS Server name and IP address will be listed.
Type "set type=mx"
NSLOOKUP will provide back the MX (Mail exchange) records from the DNS servers.
Type "hotmail.com" or your domain name.
Results will be similar to the one below:

Autodiscover service failing
Autodiscorver is a service developed by Microsoft for the Exchange servers.
It decreases the number of manual steps required by the users by providing the clients with instant access to the Exchange features.
Automatically sets up the user profile configuration for clients running Outlook as well as supported Windows Mobile devices.
Uses the user's credentials (user ID and password) to set up the profile configuration on Outlook 2013 clients and mobile devices.
When the Exchange server policies are updated (See retention tags and policies) Outlook automatically re-configures the user's Outlook profile.
It works with clients using different protocols (SMTP,POP,IMAP, MAPI etc)
Works with users applications running behind or ahead firewalls
Microsoft Remote Connectivity Analyzer Tool
The Remote Connectivity Analyzer is a collection of web-based tools provided by Microsoft to pin point network-connectivity problems affecting the Exchange Server environment.It’s easy to use and user’s friendly, let’s see how it works:
Before starting, make sure to clear the Internet Explorer cache.
Go to the upper right Settings button. Go to > Settings.(The same applies on Firefox and Chrome)

Clear Browser data > Choose what to clear.

Select all the checkboxes and click on Clear.

Microsoft Remote Connectivity Analyzer Tool
Go to https://testconnectivity.microsoft.com/

To check if the Autodiscover service works properly:Select “Outlook Autodiscover” and click on Next

Fill out the required information

Perform test.
The service will show the below notification:

Once completed, result and test details will be shown as below:

The details will help to identify the areas we need to focus to resolve the problem.
