A user account with a valid mail licence used for authentication with EWS e.g. Office 365 E3
This users email address can be used for sending and receiving email but Alemba recommends using a Shared Mailbox.
Users can be created and managed in the Microsoft 365 Admin Center.

The user must be able to login to authorize the EWS connection and must be delegated permissions to send and receive emails using the specified email address. Email Address for Send and Receive

The Mail User account and related email address may be used for sending and receiving email.

Alemba recommends configuring a shared mailbox for this purpose.

Shared Mailboxes are created in the Exchange Admin Center:

Email Address for Send and Receive

The Mail User account and related email address may be used for sending and receiving email.

Alemba recommends configuring a shared mailbox for this purpose.

Shared Mailboxes are created in the Exchange Admin Center:

Allow the “Authorizing User” to “Read and Manage” and “Send as” the Shared Mailbox using “Manage mailbox delegation”

Azure App Registration

Register an application in Azure for a Web type client. This is used to authorize the connection from ASM to EWS

Details on how to create an app registration can be found here:

Add web redirect url to the app registration in the following format: Error! Hyperlink reference not valid.
Create a client secret for the app registration. Make a note of the secret and keep it secure. You will need it later.

Configure ASM

Ensure the ASM web site has a https binding with a valid SSL certificate. This is required for the web redirect url.

Enable “Email OAuth 2.0 Support” in the Preview Features/Advanced Features of system admin. You may need to log out for the changes to take effect.