Ohio University

Login security improvements will affect older email/calendar apps

This page was updated March 30, 2020.

On October 13, 2020, Microsoft will stop supporting Basic Authentication, an older, less secure way of accessing Office 365 services. When these changes take effect, some older email and calendar clients and mobile apps will stop working with Office 365.

To provide time for everyone at the University to adapt to this change, OIT originally recommended switching to a supported email/calendar client by March 31, 2020; however, with the recent transition to online instruction and remote work, we have postponed this change until after the end of spring semester 2020.

To find out if this change will affect you and what you will need to do, see Recommended Steps below. 


Ohio University's email and calendar are hosted in the cloud via Microsoft's Office 365 online collaboration suite. Being a part of Office 365 gives Catmail a great deal of reliability and flexibility, but it also means that we need to keep up with Microsoft's system requirements.

Historically, Microsoft has supported many ways of accessing email and calendar. The best, of course, are Microsoft Outlook, Outlook Mobile, and Outlook on the Web, but other clients and apps also can be made to work with Office 365. These include the Mail and Calendar apps that come with MacOS, iOS, and Android, as well as older desktop applications like Eudora, Pine, and Thunderbird.

With cyber attacks becoming not only more common but also more sophisticated, Microsoft has decided to phase out an older way of logging in that it considers less secure. This is a good thing. To read more about Microsoft's technical and security reasons for this decision, visit Improving Security - Together

Unfortunately, for some individuals this means that their favorite method of checking email or calendar may stop working. In some cases, a settings update and/or an operating system upgrade may be required. In other cases, the only option will be to switch to a supported client.

Recommended steps 

If you have more than one way of checking your OHIO email and calendar, you may need to take different steps for each device or application that you use.


Outlook on the Web

If you use a web browser to check your mail/calendar at https://catmail.ohio.edu, then you do not need to do anything. Outlook on the Web already uses Microsoft's secure login.

Outlook for PC and Mac

Depending on which version of Outlook you are using, you may need to upgrade. 

Outlook Mobile Apps

The Outlook mobile apps for iOS and Android are fully compatible with Microsoft's secure login requirement. If you are using Outlook on a mobile device, no action is needed.

Other Mail and Calendar Applications

Mac Mail and Calendar 

  • Mac OS 10.14 (Mojave) and newer: The Mail and Calendar apps that come with Mac OS 10.14 (Mojave) and Mac OS 10.15 (Catalina) will continue to work. Depending on how you originally set up your Mac, you may need to delete and re-add your email/calendar account profile to avoid a service interruption. 
  • Mac OS 10.13 and older: The built-in Mail and Calendar apps that came with Mac OS 10.13 or older will not work. To continue using those apps, you will need to upgrade your Mac OS, or you can switch to using Outlook for Mac or Outlook on the Web.  

IMAP/POP Applications like Thunderbird, Eudora, PINE, etc.

Email applications that use Basic Authentication in combination with POP, IMAP, or Exchange ActiveSync will stop working. Examples include Thunderbird, Eudora, PINE, and the current POP version of Gmail's "Check mail from another account" feature. If your application's developer offers a version that supports Modern Authentication, you can upgrade. If an updated version is not available, we recommend switching to the latest version of Outlook or using Outlook on the Web. 

Important Note for POP Users

Many POP clients delete messages from the server once they have been downloaded to your computer. To avoid losing saved messages, make sure you have backed up your locally stored messages before uninstalling your old email client. The IT Service Desk can help you with this process.

iOS Mail and Calendar Mobile Apps

  • iOS 11 or newer: The Mail and Calendar apps that come with iOS 11 or newer will continue to work; however, you may need to delete and re-add your email/calendar account to avoid a service interruption.
  • iOS 10 and older: The built-in Mail and Calendar apps for iOS 10 and older will not work. We recommend upgrading your device to the latest version of iOS or switching to Outlook for iOS.

Android Mail and Calendar Mobile Apps

Android does not support Microsoft's new method of logging in. To avoid a service interruption, you will need to install Outlook for Android.

How to get help 

For help with this transition, please contact the IT Service Desk.