Demonstrate the email transform required for Enhanced Conversions

ec-cjs-gtm.js

// Add the below as a Custom JavaScript variable in GTM and it will use
// the Data Layer Variable "DLV - user_email" as the plaintext email input.
//
// Output will be a preformatted email address adhering to Google's
// requirements for Enhanced Conversions.
function() {
  email = {{DLV - user_email}}.trim().toLowerCase().split('@');
  return (email[1] === 'gmail.com' || email[1] === 'googlemail.com')
    ? email[0].replaceAll('.','').split('+')[0] + '@' + email[1]
    : email[0].split('+')[0] + '@' + email[1]
}

ec-demo.js

// Demo of the email transform required for Enhanced Conversions
// Copy & paste this into e.g. Chrome dev console
const userEmails = [
  "test.t.test+testing@gmail.com",
  "zaphod.beeblebrox@yahoo.com",
  "arthur.dent@googlemail.com",
  "ford.prefect+earth@planningoffice.org"
]

for (email of userEmails) {
  console.log(email + " -> " + transformEmailForEC(email));
}

function transformEmailForEC(email) {
  email = email.trim().toLowerCase().split('@');

  return (email[1] === 'gmail.com' || email[1] === 'googlemail.com')
    ? email[0].replaceAll('.', '').split('+')[0] + '@' + email[1]
    : email[0].split('+')[0] + '@' + email[1];
}