When attempting to configure oAuth2 for the General Email plugin, the following error is displayed when connecting an email account;

"AADSTS9002325: Proof Key for Code Exchange is required for cross-origin authorization code redemption."

When this error occurs, please review your Azure app to ensure that the option "Web" is being utilized within the Redirect setup of the configuration rather than any of the other options available. Additionally, check that the URL is the same as that used for DocuWare.
For more on how this can be configured or adjusted, please see step 2 from KBA-36920

KBA is applicable for both Cloud and On-premise Organizations