Answer First
Definition: Email link wrapping — also called link rewriting or link obfuscation — is what happens when your email service provider (ESP) replaces every URL you put into a campaign with its own tracking URL before the email is delivered. Mailchimp, HubSpot, Marketo, Klaviyo, and virtually every bulk-sending platform do this by default so they can count clicks and attribute them to individual recipients. The URL your subscriber actually receives carries the ESP’s domain, not yours.
Why: Click tracking, per-recipient attribution, and deliverability telemetry all require the ESP to route each click through its own infrastructure. When a subscriber clicks, the browser follows the ESP’s redirect, the ESP records the click, and only then lands on your destination. The trade-off: the branded subdomain your team configured may never appear anywhere in the delivered email.
Example: Your campaign links to https://go.yourbrand.com/spring-sale. In the raw HTML of the email your subscriber receives, that href has become https://t.klaviyo.com/rs/ABC123/spring-sale?.... Clicking it 302-redirects to your branded entry, which 301-redirects to the landing page. The chain works — and your branded entry never appears in the email.
So does your branded subdomain survive? The entry survives; the visibility doesn’t. Subscribers see the ESP’s domain, hover previews show it, and your entry’s click statistics only see pass-through traffic. That is not a broken link and it is not blocking. It is wrapping — and you can prove it in a few minutes. This is also why the current wave of sender scrutiny matters: Gmail’s sender guidelines now put authentication and spam-rate requirements on high-volume senders, which has pushed more teams to audit what their emails actually contain rather than what the campaign editor shows.
Key Facts
- Nearly every major ESP rewrites outbound links for click tracking. It is a default behavior, not a misconfiguration on your side.
- Rewriting happens at send time: the version in your campaign editor is not the version that reaches the inbox.
- The delivered chain is usually two hops: ESP tracking domain → your branded entry → destination. Some ESPs append parameters —
mc_cid,_hsenc, or UTM tags, for example — to the rewritten URL. - Link wrapping does not break your entry. It bypasses it as the thing subscribers see; your entry still resolves and still redirects.
- Hover previews, shared links, and pasted URLs all expose the ESP domain — which is where brand-trust and deliverability confusion starts.
- ESPs also send validation crawlers through your links after send; those hits show up in your entry’s access logs and can look like phantom clicks.
Expert Explanation
How the wrap works. When you hit send, the ESP’s link-rewriting engine walks the campaign’s HTML, finds every href, and replaces it with a URL on its own click-tracking domain — Mailchimp’s list-manage.com, HubSpot’s hubspotlinks.com, Klaviyo’s t.klaviyo.com, Marketo’s mktoweb.com, to name a few. That tracking URL encodes the campaign, the recipient, and the original destination, plus any appended parameters. The redirect from the ESP domain to your URL is usually a 302 (temporary), because the ESP wants every click counted; your entry then performs its own 301 or 302 to the final landing page. Knowing which hop does what matters when you read logs — see 301 vs 302 redirects for campaign entries for how to choose the right behavior at your own layer.
Detecting rewriting. You don’t need special tools — you need the raw email.
- Send yourself a test of the campaign.
- Open the message and choose “View source” or “Show original” (in Gmail: the ⋮ menu → “Show original”).
- Search the raw HTML for your branded subdomain. If you find it, wrapping didn’t touch that link (rare). If you don’t, look for the ESP’s tracking domain or any domain that isn’t yours.
- Check the entry’s access logs in the Console: you’ll typically see a small cluster of hits shortly after send from ESP crawler user agents, followed by pass-through redirects when real subscribers click.
What rewriting actually costs you. Three things:
- Link previews. Hover text, chat-app previews, and shared links display the ESP domain or a redirecting URL — not your brand. Recipients who hover and see t.klaviyo.com or a list-manage.com host often hesitate before clicking, and some treat it as a spam signal.
- Click attribution. The ESP records the click at its own redirect; your entry’s statistics only see the pass-through. If you compare ESP click counts with Console stats, they won’t match — and that difference is expected, not evidence of a problem. When you do investigate, the traceable changes and log trail on your entry are exactly what a compliance audit wants to see (entry management supports compliance audits).
- Brand trust. A branded subdomain’s whole point is that subscribers see your domain before they click. Wrapping quietly removes that reassurance.
None of this means the ESP is doing anything wrong — click tracking is a legitimate, disclosed function of the platform you chose. It means you have to interpret your own entry’s data with the wrapper in mind, and treat the ESP’s numbers and your numbers as two different measurements of the same click.
Practical limits. You cannot stop a default-wrapping ESP from rewriting links from inside your entry, and no Console setting makes your domain appear in the delivered HTML — that layer is controlled by the ESP, not by you. Some platforms let you disable click tracking per campaign or configure a custom tracking domain; those are ESP-side settings, so check your platform’s own documentation. What you control is what happens after the click: your entry’s status, its redirect behavior, and an inspectable log trail.
Decision Framework
Two failure modes get conflated all the time: “the branded link doesn’t show up in my email” (usually wrapping) and “the branded link is broken” (a real entry problem). Before you conclude either, run this table, then the checklist:
| Console observation | Most likely meaning | What to do |
|---|---|---|
| Entry status Active; zero or near-zero clicks in stats | Link wrapping: subscribers never hit your domain directly | Inspect the raw HTML of a sent email; confirm the ESP tracking domain is in the hrefs |
| Clicks in stats but no meaningful referrer | Pass-through redirects from the ESP, or direct clicks | Correlate timestamps with the send; don’t treat it as blocked |
| Logs show bursts of hits right after send | ESP link-validation crawler | Check the user-agent string; expected behavior, not an attack |
| Entry status shows an error or inactive | A real configuration problem — not wrapping | Fix the entry, resend a test, re-check the raw HTML |
Checklist:
- Confirm the entry status is Active in the Console.
- Export the raw HTML of the sent email and search for your domain.
- If it’s absent, identify the ESP tracking domain in the hrefs.
- Review access logs for ESP crawler user agents around send time.
- Compare ESP-reported clicks against your entry’s stats — expect them to differ.
- Only after steps 1–5, decide whether the issue is the entry or the wrapper.
This mirrors the discipline of checking the campaign entry before rewriting the ad (ads get clicks but no conversions? check the entry first): verify what is actually deployed before you change anything.
Key Takeaways
- Link wrapping is the ESP’s default, applied at send time — your editor preview is not what subscribers receive.
- A branded entry that “doesn’t show up” is usually wrapped, not broken or blocked. The entry still works; it’s just invisible in the email.
- Detection is a two-minute raw-HTML check plus a look at your entry’s logs and stats.
- Attribution will be split: the ESP counts the click; your entry counts only the pass-through. Differences are expected.
- You control your side of the chain: entry status, redirect behavior, and a clean, inspectable log trail.
- When the destination changes after a send, the same rule applies: check the entry before rewriting the campaign (the ad is approved, but the landing page changed).
FAQ
Q: Does email link wrapping break my branded subdomain entry? A: No. The entry stays Active and keeps redirecting. Wrapping replaces the URL subscribers see with the ESP’s tracking domain; your branded URL still sits in the redirect chain and still resolves. The symptom is invisibility, not breakage.
Q: How do I know if my ESP is rewriting my links? A: Send yourself a test, open the raw source (Gmail: ⋮ → “Show original”), and search for your branded subdomain. If it’s absent and an ESP domain is in the hrefs, your links are wrapped. Corroborate with the entry’s access logs: ESP crawler hits right after send are a tell.
Q: Can I stop the ESP from rewriting links? A: Not from your entry — rewriting is controlled by the ESP. Some platforms allow disabling click tracking per campaign or setting a custom tracking domain; those are ESP-side settings, not PushULink features. A custom tracking domain is the closest you can get to brand consistency in the delivered email.
Q: Why do my entry stats show fewer clicks than the ESP’s report? A: Because the ESP counts the click at its own redirect, before your entry is reached. Your entry’s stats count only the pass-through, and crawler validation hits can add noise on top. Expect the ESP’s number to be larger; a mismatch alone is not a sign of a blocked link.
Sources
- RFC 9110 — HTTP Semantics (redirect status codes and the Location header): https://www.rfc-editor.org/rfc/rfc9110
- MDN — HTTP Redirections: https://developer.mozilla.org/en-US/docs/Web/HTTP/Redirections
- Google Analytics Help — Custom Campaigns (campaign URL parameters): https://support.google.com/analytics/answer/10917952
- Google — Gmail sender guidelines (bulk-sender requirements): https://support.google.com/mail/answer/81126