Hi @Ashlee W
Welcome to our forum!
Looks like the issue is related to the Microsoft Certification, please kindly understand that the Outlook tag here we mainly focus on general issues about Outlook desktop client. In order to better solve your problem, it's suggested to post your issue on this dedicated forum for Microsoft Certification for more professional help.
Meanwhile, there is a workaround you may refer to:
You can set the business Outlook email account as shared Mailbox with Delegate Access.
- Shared Mailbox: Create a shared mailbox for the team. This allows multiple users to access the same email account without needing to share credentials. More information: Share and access another person's mailbox or folder in Outlook - Microsoft Support
- Delegate Access: Assign delegate access to each team member. This way, they can access the shared mailbox through their own accounts, which are secured with their individual MFA setups. More information: Allow messages to be sent on your behalf when sharing a folder or mailbox - Microsoft Support
In addition, i find several similar threads you may feel free to refer to:
- MFA for one email account with several users - Microsoft Community Hub
- MFA Activation for Shared Email Address - Microsoft Q&A
Hope it helps!
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