Unfortunately it's not only the clients it's the servers as well. Also this is still occasionally an issue in Office 365
This guide doesn't look bad - https://capsulecrm.com/support/setup-and-configuration/micro...
The official Microsoft article - Change the message format to HTML, Rich Text Format, or plain text - https://support.microsoft.com/en-us/office/change-the-messag...
And of course the Microsoft Exchange article - https://docs.microsoft.com/en-us/exchange/tnef-conversion-op...
Unfortunately it's not only the clients it's the servers as well. Also this is still occasionally an issue in Office 365
This guide doesn't look bad - https://capsulecrm.com/support/setup-and-configuration/micro...
The official Microsoft article - Change the message format to HTML, Rich Text Format, or plain text - https://support.microsoft.com/en-us/office/change-the-messag...
And of course the Microsoft Exchange article - https://docs.microsoft.com/en-us/exchange/tnef-conversion-op...