Identify Email Recipients

Snitcher can detect when a user clicks a link to your website from an outbound or marketing email. This allows you to collect identities from any clicks in your email campaigns—no form submission required. This integration significantly increases your identified visitor count, helping you understand how email recipients interact with your content and product before they ever fill out a form.

Snitcher also captures all UTM parameters from email clicks, so you can attribute website activity to specific campaigns.

Why Email Identification Matters

Snitcher can usually identify which company is visiting your site, but many email clicks are harder to trace—people check emails on their phones, at home, or use privacy-focused email apps that hide their identity. Email link tracking solves this. When someone clicks a link in your email, you’ll know exactly who they are—not just their company, but the actual person. Instead of “Someone from Acme Corp viewed pricing,” you’ll see “Sarah Chen from Acme Corp viewed pricing.”

How It Works

Add a special parameter to your email links that contains the recipient’s email. When they click through:

Snitcher reads the email parameter from the URL
The visitor is immediately identified
All their activity is linked to their email address
The parameter is automatically removed from the URL (no ugly query strings)

Two Ways to Identify

Snitcher supports two methods for passing email addresses in URLs:

Option 1: Plain Email (`sn_email`)

The simplest approach—pass the email address directly:

https://yoursite.com/[email protected]

Pros: Simple to implement, easy to debug
Cons: Email is visible in the URL

Option 2: Base64 Encoded (`sn_eid`)

For better privacy and shorter URLs, encode the email as base64:

https://yoursite.com/pricing?sn_eid=c2FyYWhAYWNtZS5jb20=

Pros: Obfuscates the email address, shorter URLs for long email addresses
Cons: Requires encoding step To encode an email address:

// JavaScript / Node.js
const email = "[email protected]";
const encoded = Buffer.from(email).toString("base64");
// Result: "c2FyYWhAYWNtZS5jb20="

# Python
import base64
email = "[email protected]"
encoded = base64.b64encode(email.encode()).decode()
# Result: "c2FyYWhAYWNtZS5jb20="

Use base64 encoding when generating URLs programmatically or when you want to avoid exposing email addresses in browser history and server logs.

Platform-Specific Setup

HubSpot

Add Snitcher parameters to your Sales and Marketing email templates. For Sales Templates:

Go to Conversations → Templates
Edit your template and add the parameter to your links

For Marketing Emails:

Go to Marketing → Emails
Edit your template and add the parameter to your links

URL Parameters: If there are no other URL params:

?sn_email={{contact.email}}

If there are other URL params:

&sn_email={{contact.email}}

Using Base64 Encoding with HubSpot

For base64-encoded emails, you’ll need to create a custom property and workflow:1. Create a base64_email property in your Contact object schema.2. Create a HubSpot Workflow:Set the enrollment trigger to:

Email is known
Email has been updated in the last 1 day

Add a custom code step:

exports.main = async (event, callback) => {
  const email = event.inputFields['email'];
  const base64Encoded = Buffer.from(email).toString("base64");

  callback({
    outputFields: {
      base64_email: base64Encoded
    }
  });
}

Set the output variable to update the contact’s base64_email property.3. Update your templates to use {{contact.base64_email}}:

?sn_eid={{contact.base64_email}}

Apollo.io

Update your sequence templates to include Snitcher parameters.

Go to Engage → Sequences
Edit your email template
Add the parameter to your links

If there are no other URL params:

?sn_email={{email}}

If there are other URL params:

&sn_email={{email}}

Salesloft

Update your email templates to include Snitcher parameters.

Open the email template editor
Add the parameter to your links

If there are no other URL params:

?sn_email={{email}}

If there are other URL params:

&sn_email={{email}}

Outreach

Update your sequence templates to include Snitcher parameters.

Open your sequence in the template editor
Add the parameter to all links pointing to your website

If there are no other URL params:

?sn_email={{email}}

If there are other URL params:

&sn_email={{email}}

Mailchimp

Use merge tags to include the recipient’s email in links. If there are no other URL params:

?sn_email=*|EMAIL|*

If there are other URL params:

&sn_email=*|EMAIL|*

Customer.io

Use Liquid templating to include the email in links. If there are no other URL params:

?sn_email={{customer.email}}

If there are other URL params:

&sn_email={{customer.email}}

Marketo

Use Marketo tokens in your email templates. If there are no other URL params:

?sn_email={{lead.Email Address}}

If there are other URL params:

&sn_email={{lead.Email Address}}

Custom Implementation

For any email platform or custom-built emails, simply append the appropriate parameter to your links:

Using Plain Email

https://yoursite.com/[email protected]

Using Base64 Encoding

// Generate the encoded ID
const email = "[email protected]";
const encodedId = Buffer.from(email).toString("base64");

// Construct the URL
const url = `https://yoursite.com/demo?sn_eid=${encodedId}`;
// Result: https://yoursite.com/demo?sn_eid=cmVjaXBpZW50QGNvbXBhbnkuY29t

Adding Traits to Email Links

You can enrich identification with additional traits by adding sn_trait_ parameters to your URLs. Snitcher detects any parameter following the pattern sn_trait_<property> and includes it in the user’s profile. Example traits:

[email protected]&sn_trait_first_name=Sarah&sn_trait_last_name=Chen&sn_trait_title=VP%20Marketing

This identifies the visitor with:

Email: [email protected]
First Name: Sarah
Last Name: Chen
Title: VP Marketing

const params = new URLSearchParams({
  sn_email: "[email protected]",
  sn_trait_first_name: "Sarah",
  sn_trait_last_name: "Chen",
  sn_trait_title: "VP Marketing",
  sn_trait_company: "Acme Corp"
});

const url = `https://yoursite.com/demo?${params.toString()}`;

Common Traits to Include

Trait	Parameter	Example
First Name	`sn_trait_first_name`	`Sarah`
Last Name	`sn_trait_last_name`	`Chen`
Full Name	`sn_trait_name`	`Sarah Chen`
Job Title	`sn_trait_title`	`VP Marketing`
Company	`sn_trait_company`	`Acme Corp`
Phone	`sn_trait_phone`	`+1-555-123-4567`

URL encode trait values that contain spaces or special characters. For example, “VP Marketing” becomes VP%20Marketing.

Best Practices

Use Base64 for Programmatic URLs

When generating links via code (APIs, scripts, automation), use sn_eid to keep emails out of logs and analytics.

Test Your Links

Before sending a campaign, click a test link and verify the visitor appears identified in Snitcher.

Include Key Traits

Add name and title traits to make identified visitors immediately actionable for sales.

Combine with UTMs

Include standard UTM parameters alongside Snitcher params for campaign attribution.

Example: Complete Email Link

A fully instrumented email link might look like:

https://yoursite.com/case-studies?utm_source=email&utm_medium=outreach&utm_campaign=q1-enterprise&[email protected]&sn_trait_first_name=Sarah&sn_trait_company=Acme%20Corp

Or with base64 encoding:

https://yoursite.com/case-studies?utm_source=email&utm_medium=outreach&utm_campaign=q1-enterprise&sn_eid=c2FyYWhAYWNtZS5jb20=&sn_trait_first_name=Sarah&sn_trait_company=Acme%20Corp

Privacy Considerations

Only use email link tracking for emails you send directly to recipients. Never expose email addresses in public links, social posts, or anywhere they could be accessed by unintended parties.

Email link tracking is designed for:

Sales outreach emails
Marketing campaigns to your own lists
Transactional emails
Newsletter links

Not appropriate for:

Public landing pages
Social media posts
Shared documents
Any link that could be forwarded or shared publicly

Troubleshooting

Visitor not showing as identified

Verify the parameter name is correct (sn_email or sn_eid)
Check that the Snitcher tracker is installed on the landing page
Ensure the email format is valid
For base64, verify the encoding is correct (no padding issues)

Base64 encoding not working

Make sure you’re using standard base64 encoding. Test your encoding:

// Encode
const encoded = Buffer.from("[email protected]").toString("base64");
console.log(encoded); // "dGVzdEBleGFtcGxlLmNvbQ=="

// Decode to verify
const decoded = Buffer.from(encoded, "base64").toString();
console.log(decoded); // "[email protected]"

Traits not appearing on profile

Ensure trait parameters follow the sn_trait_ prefix pattern
Check that values are properly URL encoded
Traits should appear within a few minutes of the click

Parameter still visible in URL after page load

Snitcher automatically removes identification parameters from the URL. If they persist:

Check that the tracker script is loading correctly
Verify there are no JavaScript errors on the page
Ensure the tracker version is up to date

Next Steps

Identify Users

Learn about the identify() method for form and login identification

Custom Events

Track specific actions taken by identified visitors

Get Started

Tracker

Spotter API

Integrations

Why Email Identification Matters

How It Works

Two Ways to Identify

Option 1: Plain Email (`sn_email`)

Option 2: Base64 Encoded (`sn_eid`)

Platform-Specific Setup

HubSpot

Apollo.io

Salesloft

Outreach

Mailchimp

Customer.io

Marketo

Custom Implementation

Using Plain Email

Using Base64 Encoding

Adding Traits to Email Links

Common Traits to Include

Best Practices

Use Base64 for Programmatic URLs

Test Your Links

Include Key Traits

Combine with UTMs

Example: Complete Email Link

Privacy Considerations

Troubleshooting

Next Steps

Identify Users

Custom Events

Get Started

Tracker

Spotter API

Integrations

​Why Email Identification Matters

​How It Works

​Two Ways to Identify

​Option 1: Plain Email (sn_email)

​Option 2: Base64 Encoded (sn_eid)

​Platform-Specific Setup

​HubSpot

​Apollo.io

​Salesloft

​Outreach

​Mailchimp

​Customer.io

​Marketo

​Custom Implementation

​Using Plain Email

​Using Base64 Encoding

​Adding Traits to Email Links

​Common Traits to Include

​Best Practices

Use Base64 for Programmatic URLs

Test Your Links

Include Key Traits

Combine with UTMs

​Example: Complete Email Link

​Privacy Considerations

​Troubleshooting

​Next Steps

Identify Users

Custom Events

Why Email Identification Matters

How It Works

Two Ways to Identify

Option 1: Plain Email (`sn_email`)

Option 2: Base64 Encoded (`sn_eid`)

Platform-Specific Setup

HubSpot

Apollo.io

Salesloft

Outreach

Mailchimp

Customer.io

Marketo

Custom Implementation

Using Plain Email

Using Base64 Encoding

Adding Traits to Email Links

Common Traits to Include

Best Practices

Example: Complete Email Link

Privacy Considerations

Troubleshooting

Next Steps