Overview
Users can configure their Email preferences to set new appointments as online meetings or not. When a customer creates a new appointment in Outlook, and adds one or more attendees to the appointment, Outlook will automatically set such appointments as online meetings in the meeting client of the users choice.
Here is how an online meeting looks:

How to configure online meetings by default
The user only needs to set this preference in one place. Their Outlook clients will synchronize the setting.
Select the gear icon, then "View all Outlook settings".

Select "Calendar", then "Events and invitations". The option is under "Events you create".

When the option "Add online meeting to all meetings" is NOT selected, new appointments will not be set to online meetings by default; the user can still set created appointments as online on an appointment by appointment basis.
When the option is selected, the user can select from a list of installed online meeting providers such as Zoom and Teams. In this example, only Microsoft Teams is available.

Once the user has made their selection, they must click "Save".
Outlook for MacOS
With Outlook for MacOS opened, select Preferences from the menu bar, under "Outlook".

In Outlook Preferences, click on "Calendar" under "Other".

Under "Calendar Options", Click on the "Configure..." button next to "Add online meeting to all events".

The setting can be found in the "Online meeting" window.

Outlook Desktop App for Windows
Right click on the Calendar in the left side navigation and select "Options..."

Click on "Add Meeting Provider..."

The "Online Meeting" dialog will provide available options to enable or disable online meetings.

Exchange Online global setting for Online Meetings by Default
In order to enable users to select whether or not they wish to have online meetings by default, we have set the global Exchange option "OnlineMeetingsByDefaultEnabled" to False.
This is done with Powershell and the Exchange powershell module, using the Set-OrganizationConfig commandlet. Here is an example of making the setting and viewing the result.
Connect-ExchangeOnline
Set-OrganizationConfig -OnlineMeetingsByDefaultEnabled $false
(Get-OrganizationConfig).OnlineMeetingsByDefaultEnabled
There are three places that Online Meetings by Default can be set, at the global level, at the mailbox level, and at the mail client level. Microsoft support provided the following table of the expected behavior of the setting depending on what these three places have set.
Tenant Setting
|
Single user Mailbox setting
|
Single user Outlook setting
|
Expected behavior
|
OnlineMeetingsByDefaultEnabled
|
OnlineMeetingsByDefaultEnabled
|
(Set-Organizationconfig)
|
(applied with powershell)
|
FALSE
|
FALSE
|
FALSE
|
Meetings will not be created Online ( Teams Meeting )
|
FALSE
|
FALSE
|
TRUE
|
Meetings are created Online ( Teams ) for this User
|
FALSE
|
TRUE
|
FALSE
|
Meetings are created Online ( Teams ) for this User
|
FALSE
|
TRUE
|
TRUE
|
Meetings are created Online ( Teams ) for this User
|
TRUE
|
FALSE
|
FALSE
|
Meetings are created Online ( Teams ) for this User
|
TRUE
|
FALSE
|
TRUE
|
Meetings are created Online ( Teams ) for this User
|
TRUE
|
TRUE
|
FALSE
|
Meetings are created Online ( Teams ) for this User
|
TRUE
|
TRUE
|
TRUE
|
Meetings are created Online ( Teams ) for this User
|