Microsoft reports that the fix has been deployed to all affected servers.
Microsoft has a fix for the issue and will deploy it as soon as possible. Users may still experience issues until the fix is deployed.
The cause of the issue was a recent update to the Exchange Online service. Affected users may use OWA (https://office365.uiowa.edu) until the fix is deployed.
Some users have reported that they are repeatedly getting prompted for their password in Outlook. ITS is investigating the issue. The following support article has solutions for resolving the issue: https://its.uiowa.edu/support/article/103549