How to Disable IMAP, POP, and SMTP Protocols Across your Organization

Here are the instructions on how to disable IMAP, POP, and SMTP protocols across your organization.

Install the Exchange PowerShell Module

1. Log in to https://outlook.office365.com/ecp with Microsoft Edge (not Chrome or Safari)
2. Click on Hybrid
3. Click on Configure under The Exchange Online PowerShell Module supports multi-factor authentication. Download the module to manage Exchange Online more securely.
4. Install the module

Connect via PowerShell

1. Connect-EXOPSSession -UserPrincipalName UserPrincipalName
2. Connect-EXOPSSession -UserPrincipalName enter your email here

Create the authentication policy

To create a policy that blocks Basic authentication for all available client protocols in Exchange Online (the recommended configuration), use the following syntax:

New-AuthenticationPolicy -Name "<Descriptive Name>"

This example creates an authentication policy named Block Basic Auth.

New-AuthenticationPolicy -Name "Block Basic Auth"

Configure the default authentication policy

The default authentication policy is assigned to all users who don't already have a specific policy assigned. Note that the authentication policies assigned to users take precedence over the default policy. To configure the default authentication policy for the organization, use this syntax:

Set-OrganizationConfig -DefaultAuthenticationPolicy <PolicyIdentity>

This example configures the authentication policy named Block Basic Auth as the default policy.

Set-OrganizationConfig -DefaultAuthenticationPolicy "Block Basic Auth"