In the Outlook Options dialog box on the Mail page, click the Compose messages in this format drop-down arrow in the Compose messages section. Then, choose a format from the list HTML , RTF , or ...

If Outlook signature format changes when replying or forwarding an email, copy your signature in Notepad and paste it back, ...

Clear the box next to "Don't Download Pictures Automatically in HTML E-mail Messages or RSS Items." Click "OK" to return to your mail. Any HTML messages you open will no longer display as plain text.

Mozilla recommends sending your messages as ordinary text if you're not sure if your recipient's email client or program can process HTML. After selecting a format setting, you have the option to ...