How to disable html format in OWA

[TechAB]

Hi Folks, 

Is there a way we can disable HTML formatting in OWA organization wide?

We can make changes per users basis on https://outlook.office.com/mail/options/mail/messageContent but we rather like a way to disable the HTML emails for everyone in the organization - I looked up for a related attribute in OrgConfig/remote domain and OWAMailboxPolicy but found nothing related. 

Any help would be appreciated. 

[#2]

You can toggle this on/off via PowerShell, so it's easy to automate across multiple users:

Set-MailboxMessageConfiguration user -DefaultFormat PlainText

Note that this setting only applies to OWA.

[#3]

This indeed helps us but we wanted a way to disable HTML formatted emails both incoming and outgoing. Is there a way this can be achieved? 

[#4]

Hi @TechAB,

in other words you wish to convert all ingoing emails from HTML to  the plain text. correct?

If so you have to create a custom transport agent (if you are running on-premise Exchange server).

[#5]

Yes, that is correct. I want to convert all incoming/outgoing emails from HTML to Plain text. I am completely EXO. 

[#6]

If EXO means Exchange online then the only way I can see is creating a custom Power Automate flow.