How to make a phone number callable on mobile devices in newsletters?

Question

These are the various options that i have tried using table structure for newsletters. My problem is that on the click of the phone number on mobile devices and it redirects to a new page having the callto or tel in its url, whereas in browsers it redirects to a blank page. Help me out on this.

<a href="tel:9865551555">9865551555</a>
<a href="callto:9865551555">9865551555</a>

Answer 1

Be sure to include the country code. The format found in this tutorial worked well for me.

<a href="tel:+19865551555">(986) 555-5155</a>