Some notes on fixing the calendar and contacts along with the email account on local machines or devices.
Because many clients have problems connecting with the new Microsoft 365 system, for hosting the dns settings are important;:
https://learn.microsoft.com/en-us/microsoft-365/admin/get-help-with-domains/create-dns-records-at-any-dns-hosting-provider?view=o365-worldwide
When email is used on a specific domain a calendar and the contacts can be shared through the WebDav protocol.
Setting up the calendar (calDav) and contacts (cardDav) on IOS and Mac is easy, making things work with Microsoft Outlook might be a bit difficult.
To setup a connection first the server-side (webhost) needs to provide specific WebDav links for sharing the calendar and contacts.
Ie. this can be set with the CPanel calendars and contacts option if the calendar-and-contacts-server plugin is installed.
For IOS/Mac/Android:
> See the instructions from CPanel (scroll halfway the page)
For Outlook:
the WebDav protocol needs to be installed through an extension called caldavsynchronizer. (also available at sourceforge.net)
> Download and install the caldavsynchronizer and follow these instructions
There is a lot more to this, ie. CPanel webmail Horde application can be used to test the shared contacts and calendars.