Hi David,
Thanks for visiting our forum, here we mainly focus on general issues about Outlook desktop client.
>> When signing into Outlook, the users are prompted to download and install the Microsoft Authenticator app but I'm not sure why that is.
Are you using an Exchange account?
Does this issue only happen to your Outlook for mobile client? It is suggested to add your email account to the mail client that comes with your phone and see if the issue has any difference. If they can all work fine on the mail client that comes with your
phone and only have issues when using outlook app, I'm afraid that your issue may be related to the Outlook for iphone app.
Besides, as I know, if your email account has enabled two-factor verification, you will need the Microsoft Authenticator app when log in to your email account. Please check if you have enabled this feature in these email accounts and you could disable this
feature if you really don’t need it. For more information, you may check this article:
What is the Microsoft Authenticator app?
If your issue still continues, to better solve it, it is suggested to post a new thread to the dedicated forum for
Outlook for iphone.
The reason why we recommend posting appropriately is you will get the most qualified pool of respondents, and other partners who read the forums regularly can either share their knowledge or learn from your interaction with us. Thanks for your understanding
and hope your question will be resolved soon.
Regards,
Jeff Yang
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