Des DMS have plan to support external identity provider via OAuth2 /OIDC/ SAML

[WestFarmer]

from roundcube wiki

XOAUTH support for both IMAP and SMTP servers Roundcube connects to

does DMS's underlying IMAP and SMTP server support XOAUTH ?

[polarathene]

There is an existing issue and WIP PR open regarding OIDC.

AFAIK, no one has enough time to work on the feature support presently so it's slow progress. Maybe next year,