Question from Reddit:
I have a client that has their email address listed on several pages on their site. They are paying for Google Ads and I’m wondering if there is a standard way to track conversions from people that click on a Google ad to visit the client’s site, and ultimately end up emailing them.
The client doesn’t want to use a contact form on their site. I know you can track clicks on specified HTML elements via GTM (e.g., a “mailto:” link), but the user might not follow through on actually sending the email after clicking on it., so it’s not a true conversion.
How would I display a different email address on a website depending on whether the visitor came from a Google Ad click versus something else like SEO or direct traffic? Like CallRail, but for email addresses? In other words, for visitors arriving via Google Ads, display “sales@client.com” versus all other visitors seeing [“info@client.com](mailto:”info@client.com)”.
Thanks in advance!
Answer from Nabil:
The short answer is:
You are correct that simply tracking a click on a mailto: link isn’t a true conversion because it doesn’t confirm the email was sent.
The best, most reliable solution is to implement Email Address Substitution, a technique similar to CallRail’s phone number tracking, which uses a unique, dedicated email address displayed only to users who arrive via a Google Ad.
You would use Google Tag Manager to detect the Google Ads click identifier (gclid) or a custom UTM parameter, and then dynamically replace the public email address on the webpage with the dedicated one.
The ultimate conversion tracking is achieved by having that dedicated mailbox automatically forward all received emails to your client and then sending a confirmation signal to Google Ads using the Google Ads API from a server-side environment like Stape or Google Cloud Platform.
The long answer is:
This is a classic challenge in digital marketing, especially for businesses that prefer email communication over contact forms.
Your instinct to display a different email address based on traffic source is the most reliable way to achieve this kind of conversion tracking without a form.
Since the client is using Google Ads, auto-tagging provides the essential gclid parameter, which we can use as the signal.
To implement Email Address Substitution, you’ll use Google Tag Manager to execute a client-side script that performs the dynamic swap.
First, the script checks for the presence of the gclid parameter in the URL or looks for a specific UTM parameter that is only used for your Google Ads traffic.
If the parameter is present, GTM uses a Custom JavaScript Variable to pull the unique Google Ads email address (e.g., ads-sales@client.com).
This script then finds the displayed email address’s HTML element on the page and replaces both the visible text and the underlying mailto: link with the unique address.
All other traffic will continue to see the standard info@client.com.
The true conversion tracking is then handled by the dedicated email address.
You must set up the ads-sales@client.com mailbox to have a two-part function: first, it automatically forwards the message to your client’s main inbox so they don’t miss the lead, and second, it triggers a server-side process to report the conversion back to Google Ads.
This process, ideally hosted on a robust platform like Stape’s server-side GTM or Google Cloud Platform, receives the incoming email and then uses the Google Ads API to send an Offline Conversion event.
Since the initial click was auto-tagged, Google Ads already has the gclid, and by sending the conversion event with the correct gclid, you close the loop, reporting a confirmed email lead that originated from a specific ad click.
This solution is superior to simple mailto: click tracking because it measures a completed action (an email received) and is much more scalable and reliable than manually tagging every ad.
About The Author
