Step 1: Log in to Office 365 and go to the admin centre page
Click on the grid on the top left corner and choose Admin.
Step 2: On the left menu, go to Azure Active Directory
On the left menu, click on Show all
Scroll down a bit and click on Azure Active Directory
You land on a new page, click on Azure Active Directory on the left menu
A new menu appears, scroll down and click on Properties
Step 3: Disable security defaults
On the bottom, click on Manage Security Defaults
Select No within the right-hand slider window
Save
Step 4: Go to the email settings of the email account you want to connect
On the left menu, click on Users > Active Users. Choose the account you want to connect by clicking on it, you should see a flyout coming from the right, click on Mail > Manage Email Apps
Step 5: Make sure IMAP is activated
On the new flyout on the right, make sure IMAP is checked like on the screenshot below. Then click on Save Changes. You should see a confirmation message highlighted in green telling you the information has been updated.
NOTE: If you have 2-Factor Authentication (2FA) enabled or a Single Sign-On enabled, you need to create an App Password by following the instructions below.
OR
Step 6: Provide the details to MassMailer
Provide the following details to MassMailer in order to set up the MassMailer Inboxing Service.
First Name, Last Name, Email Address, Password