Hi,
In my testing, if the email body is empty in outlook, then the email body is also empty when tracked to Dynamics CRM.
Except in this one case, the body of the email will not be empty in CRM.
Whether the problematic emails have common characteristics, such as coming from a particular email address, containing a particular email address among the recipients, etc.
You can check if there are automation flows, workflows, or plugins in your environment that are used to perform the deletion of the body of a specific email when it is created.
And whether there is any custom JavaScript added to the email form that causes the body to be deleted after the email record is loaded.
Best Regards,
Dengliang Li