A user asked:
"I have my email address in my Outlook signature without a link and blue underline. When I compose email, it looks fine. However, the recipients get a link with a blue underline. How do I control this? "
As long as you use HTML message format, you can control the link color by formatting the link so its the same color as your text. To do this, enter the URL, hyperlink it (press Enter or space bar after typing the URL) then use the format painter to paint the link the same as the other text in your signature. When you format links after the hyperlink is created, the link picks up the format used by the text. When you format the text first then create the hyperlink, it picks up the hyperlink style.
If you use plain text, you can't control if the other client hyperlinks it, other than by making the link so its not recognizable as a URL. However that makes it harder for people who might want the convenience of clicking the link to send you a new message.