Due to a change from Mircosoft, there may be problems with the delivery of emails to the CRM module.

Probably the message "Cannot open mailbox in System API Mail using IMAPSSL: Array ( [0] => Can not authenticate to IMAP server: AUTHENTICATE failed. )" is displayed in the log.

The problem can be fixed as follows:

Dialing in on the Microsoft 365 Admin Center: https://admin.microsoft.com/Adminportal

Go to the green Help / Support icon

"Diag: Enable Basic Auth in EXO" type in the dialog box:

Then "Run Tests":

Re-enable IMAP Protocol:

You can also download the instructions as a PDF.