Before you begin configuring your system, please make sure you have addressed all the Prerequisites!
Microsoft has decided to disable the basic SMTP type of authentication as of October 2020 for Microsoft 365. There is another type of authentication used with Microsoft 365 called OAuth2. See below for steps required to enable this authentication mechanism.
You are already used to OAuth if you use some of the O365 products online (e.g. Outlook).
You can read more about OAuth here:https://en.wikipedia.org/wiki/OAuth
In order to allow Agendex access to Exchange mailboxes in Microsoft 365, you need to register the application in your Azure Active Directory.
There are two types of Azure applications – single tenant and multi-tenant apps.
Agendex is configured as a multi-tenant application and has a very simple mechanism to request you to give the consent required so your instance of Agendex can access Exchange via EWS.
With multi-tenant apps you do not need to make any changes in your Azure AD manually, the application takes care of this, while Microsoft is asking you to grant the consent in a browser pop-up. Note that you will need to grant consent using an account with Global Administrator rights!