How to check IMAP connection settings when migrating emails from other platforms to Microsoft Exchange

How to check IMAP connection settings when migrating emails from other platforms to Microsoft Exchange

Microsoft offers tools to help you migrate other email service providers to Microsoft Exchange Server Mail. 
One of these tools is named IMAP Email. This tool allows you to test the connection to the mailbox from which you are migrating. For example, Yahoo Mail.

There are other tools as well, like Exchange ActiveSync (mobile devices check) among others. 

Here is the link to access the tools.