Step 1: Sign in to your account at https://azure.microsoft.com/en-us/features/azure-portal/
Step 2: Search and open the Active Directory Manager.
Step 3: Scroll down on the left panel and click on Properties.
Step 4: At the bottom click on Manage Security defaults.
Step 5: Disable security default and choose My Organization is unable to use critical business applications.
Step 6: Provide the following information to the MassMailer Support team:
You should now be able to connect your account to MassMailer Inboxing Service.
First name: Email account first name
Last name: Email account last name
Email: Email account to warm up
IMAP server: imap.secureserver.net
IMAP port: 993
IMAP Username: Your email
IMAP Password : Your email password