The best replacement for email address is username.

The best alternatives to email address are rated as following:
★★★★★  username
★★★★  phone number
★  contact form
★  screen name
★  address
★  apple id
★  email id
  phone number:
  url
  unsubscribe
  email address
  windows live messenger id

Your alternative for email address is not listed? Suggest!
Speaking about email address, one probably shouldn't forget about spam.

Other search terms related to email address and their ratings are:
★★★★★ spam
★★ domain name free
★ sending email
You have in mind a companion for email address and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of email address in all years. Click on graph for more.
email address
username
phone number