Do you carry a phone that also receives e-mail? Do you ever receive an e-mail and then want to call the person back? If they put their phone number in their e-mail signature line, you can click the e-mail to place the phone call.
If you want to, start setting the example by setting up your automatic e-mail signature line to include your phone number. Then, when you e-mail someone, they can just tap on your phone number in your e-mail signature line to reach you.
I receive so many e-mail messages that say, “Mike, call me!” and there is no number to click on. Of course I go look up their number – it would be so much faster if they listed their number.