You can change the format of a message when you reply to it or forward it. If someone sends you a plain text message, for example, you can reply to that message or forward it by using HTML or Rich Text Format. How the message appears to the person receiving it depends on their email program. If the recipient's email program is set to convert messages, for example, then a message you send formatted
![Change the message format to HTML, Rich Text Format, or plain text - Microsoft Support](https://cdn-ak-scissors.b.st-hatena.com/image/square/50a62e5e1b1c0889cadac97e7ee767f219883893/height=288;version=1;width=512/https%3A%2F%2Fsupport.office.com%2FSocImages%2FSOC_SharingImage_720x405.png)