If your text in the signature has an address, looks like a url eg. xyz.com or a telephone, many browsers will take the text and make it an active link. On the iPhone it means, tapping on an address brings up Google Maps and tapping on a telephone number will bring up the phone dialer. In Yahoo mail, clicking on the telephone number will ask you to add the number to your contacts.

The above actions by Apple Mail, Gmail or Yahoo is done at the recipient end. While we can force the display to black and not underlined, we believe there is more value for the recipient to know that these are live links that have additional functionality specific to the mail application.

Note: In the Apple Mail application, the entire line on which the telephone number is on is underlined and not just the number. Other browsers like Yahoo will only underline the number. Unfortunately this is out of our control.