Email in web analytics is an acquisition channel: traffic that lands on your site after a user clicks a link in an email message (newsletter, lifecycle campaign, CRM blast, etc.). In practice, analytics platforms recognize this channel almost entirely by tagging links with UTM parameters. The most common convention is utm_medium=email. With consistent tagging you can analyze email-driven sessions, conversion rate, revenue, and compare it to other sources like organic search, paid search, referral, display advertising, or affiliate.
Why tagging matters
Email clients typically don’t pass a referrer. If you don’t tag, those clicks often show up as direct. Sometimes ESP redirect domains can appear as “Referral,” polluting attribution. Clean, consistent UTM tagging keeps your “Email” channel accurate and separates it from other mediums like social media / paid social.
Minimal tagging schema (recommended)
| Field (UTM) | Example | Purpose |
|---|---|---|
utm_medium | email | Classifies the traffic as Email (channel logic) |
utm_source | newsletter, crm, sales | Identifies the sender/system |
utm_campaign | spring_promo_2025 | Groups a specific campaign |
utm_content (optional) | cta_top, footer_link | Distinguishes link variants for CTR tests |
Core calculations (web-side)
- Email share of traffic:
Email sessions / All sessions × 100%
Example: 1,250 / 10,000 = 12.5%. - Email conversion rate (same definition as global Conversion Rate):
Conversions from Email / Email sessions × 100%.
What to look at
- Acquisition: sessions, users, new vs. returning, first-touch vs. last-touch lifts (consistency beats perfection).
- On-site behavior: landing page performance, depth, micro-conversions.
- Commercial impact: conversions, AOV, revenue; segment by campaign, audience, or content.
Common pitfalls
- No UTMs → traffic leaks into Direct.
- Inconsistent mediums (
e-mail,Email,nl) → broken channel grouping. - Over-counting clicks vs. visits: email-side opens/clicks ≠ web-side sessions; treat CTR as a campaign diagnostic, not a site KPI.
Pro tip: Standardize utm_medium=email and maintain a controlled vocabulary for utm_source/utm_campaign. Clean taxonomy today saves you weeks of retro cleanup tomorrow.