We are observing users outside organization and added as contact, and part of a Distribution list are receiving emails in plain text format.
We are unable to replicate the issue as the users randomly receive emails in plain text format and they are not repetitive all times.
Exchange version 2010 Outlook version 2010
we tried to add the users as contact and edit the properties to always send rich text email, but it didnt work.
i need assistance to find the root of the issue and provide a solution, anticipating any help.