How to use Duo 2FA for Office

What is Duo 2FA?

Passwords are essential for security and privacy, but they are often not enough. Two-factor authentication requires something you know (your Clemson password) and something you have (like a mobile phone, landline phone or the Duo smart phone app) as an added layer of security to prevent anyone else from accessing your account. Two-factor authentication is the most effective method of account takeover prevention, helping to protect both you and the Clemson community.

Why do I need Duo on my email and Office 365 account? 

Implementing Duo on Office 365 and email can help prevent unauthorized access to your email and files, even if your password has been compromised. Sophisticated phishing attacks that successfully steal your credentials can automatically login to your Office 365 account from the attacker’s location. The attacker would be unable to complete the Duo authentication and your Office 365 account would be protected from compromise.

Will this affect what email client I can use?

The support clients are as follows:

Client Application

Full Support

Limited Support

Not Supported

Outlook 2016/2019/365 for Mac or PC




Outlook for iOS and Android




Outlook on the Web (OWA)




Native for macOS

macOS 10.14 + 

 macOS 10.13 and older *


Native Mail app for iOS

iOS 11.x +

iOS 10.3.3 and older *


Native Android Mail app


Android Mail App *


Evolution for Linux


evolution-ews 3.27.91 +






POP/IMAP and SMTP only clients




*Applications with limited support using ActiveSync technology (basic authentication) will be phased out in the future. Please make plans to use a supported email client to avoid losing email functionality.

When will I have to begin using Duo for Office 365? 

All users will use Duo for Office 365 by April 24, 2019. 

When will I get the Duo prompt for Office 365? 

You should only be prompted for Duo authentication when not connected to a Clemson wired, wireless (eduroam), or VPN network and attempting to connect to an Office 365 application or email for the first time via phone, tablet, or computer. You may also be prompted for Duo if your device has not recently connected to an on-campus network. Some legacy clients that do not support Duo authentication will not prompt you and you can continue using them as normal.

What happens if I get the Duo prompt and I’m on-campus and not trying to login to my email or an Office 365 app? 

If you receive a Duo authentication prompt (push, text, or phone call) on your device without logging into a corresponding service that requires Duo, decline the Duo prompt (marking it as fraud) and immediately change your Clemson password. This is an indication that your credentials have been compromised and attackers are attempting to login to your Duo-protected account. Contact the CCIT Service Desk for further instructions.  


For more information email or call 864-656-3494.

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