@cluster ,

We have already noticed this microsoft office 365 error in swiftmailer and mailbox option.

So we have added a neccessary changes with added new feature of MS-apps in our opensource uvdesk. But it is not an official release for this feature. We have added in v-1.2.x-dev uvdesk.

If you can install the v-1.2.0 project using the below command:

$ composer create-project uvdesk/community-skeleton:dev-master;

We would request you try the new updates and let us know if you come across any notable issues which we can address right away during our testing phase.