Is Resend Tracking Your Email? How to Block It

Resend email tracking is not running unless the sender switched it on, which is also why the usual advice to block email tracking by blocking a vendor's domain does not work cleanly here. Resend is a developer email API rather than a marketing suite. Password resets, receipts and magic links go out through it, and whether the message in front of you carries a pixel depends on a choice its sender made. That is genuinely different from most platforms, where tracking is the factory setting and switching it off is the deliberate act.

Key Takeaways

• Resend's Open and Click Tracking documentation states that open and click tracking is "disabled by default for all domains."
• Turning it on takes two steps: the open_tracking or click_tracking setting enabled on the domain, plus a verified tracking subdomain such as links.example.com pointed by CNAME at links1.resend-dns.com.
• Because tracked links use the sender's own subdomain, a tracked Resend message carries no visible resend.com hostname, so there is no single vendor domain a blocklist can match.
• Resend's documented email.clicked payload includes ipAddress, link, timestamp and userAgent, while the documented email.opened payload carries message metadata without those device fields.
• Apple Mail Privacy Protection preloads remote images through Apple's proxy, firing open pixels for messages nobody read and making 2026 open data unreliable on its own terms.

Does Resend Track Email Opens and Clicks?

Only if the sender turned it on. Resend's official tracking documentation is blunt about the default: "Open and click tracking is disabled by default for all domains."

Both settings live at the domain level, not the message level, so the mail you get from a given Resend customer is generally all tracked or all untracked. Here is what each does when switched on, in Resend's own words:

• Open tracking. "A 1x1 pixel transparent GIF image is inserted in each email and includes a unique reference to this image file. When the image is downloaded, Resend can tell exactly which message was opened and by whom."
• Click tracking. "Resend modifies each link in the body of the HTML email to point to your tracking subdomain. When recipients clicks a link, the request is redirected to your tracking subdomain, their click event is recorded, and they are redirected to the original URL."

Note the phrase "by whom." The pixel is an identifier tied to one message and one address, the same design as Amazon SES open and click tracking.

What Domain Serves the Resend Tracking Pixel and Links?

The sender's own subdomain, not a domain that looks like Resend. The documentation lists two conditions for tracking to work: the tracking setting enabled on the domain, and "a tracking subdomain is configured (e.g., links.example.com) and successfully verified." Once verified, "all tracked links in your emails will use your tracking subdomain (e.g., links.emails.example.com)."

The DNS record Resend documents for that subdomain is a CNAME with the value links1.resend-dns.com. That target is the one durable fingerprint available to you: the hostname in the message belongs to the sender, but a DNS lookup on it resolves toward Resend infrastructure.

One thing we could not verify: the public docs describe no fallback shared tracking host for senders who skip the custom subdomain, and do not separately name the hostname serving the open pixel. We could not confirm a public Resend owned tracking host, so we will not invent one for you to search for.

Resend did not build the CNAME model to evade blockers; senders adopt custom tracking domains because a mismatched link hostname hurts deliverability and looks like phishing to filters. The side effect still cuts against you. A tracked Resend message looks, in the raw source, like a normal message from that company, with no shared vendor hostname to add to a list, which is the structural problem in our piece on link wrapping and click tracking. Good engineering hygiene and effective tracker evasion turn out to be the same configuration.

What Does a Resend Open or Click Event Actually Record?

A click records more about you than an open does, which is the reverse of what most people assume. Resend's webhook event types include email.sent, email.delivered, email.bounced, email.complained, email.opened and email.clicked. Any sender can point those at their own server and keep the results forever.

The email.clicked payload documents a click object containing four fields:

• ipAddress — the network you clicked from, which maps to a city and often an employer.
• link — which specific URL you chose, not just that you clicked something.
• timestamp — the moment of the click.
• userAgent — your browser and operating system.

Resend's documented email.opened payload, by contrast, shows message level fields such as email_id, created_at, from, to and subject without the ipAddress and userAgent that appear in the click event. That is a published example payload, not a guarantee about everything logged internally, so read it as what Resend documents rather than the outer limit of what exists.

The hierarchy is clear enough: loading images tells a sender you opened the message, while clicking a link hands over your IP address, your device and your choice of destination.

Why Is Open Data Unreliable in 2026 Anyway?

Because Apple broke the metric in 2021 and nobody has fixed it since. Apple's Mail Privacy Protection preloads remote content, tracking pixels included, through Apple operated proxy servers, so a message registers as opened shortly after delivery whether or not a human looked at it, with the real IP address hidden behind Apple's.

Gmail's image proxy does something adjacent, caching remote images on Google servers. Between the two, a large share of every open number in every dashboard is machine generated, as we set out in our breakdown of Apple Mail Privacy Protection and fake email opens.

There is a quiet irony in Resend's own guidance. The docs suggest "only tracking open rates for Broadcasts to ensure that inbox providers do not mistakenly identify your transactional emails as marketing emails." Read that from the recipient's side: the reason to skip open tracking on your password reset email is not privacy, it is that pixels make mail look like marketing and hurt inbox placement. Deliverability pressure is doing more to keep pixels out of transactional email than any privacy argument has managed.

How Do You Tell If a Resend Message Is Tracking You?

Read the raw message source, which is the only place the answer is written down. In Gmail on desktop:

• Open the message, click the three dot menu at the top right of the message pane, and choose Show original.
• Press Ctrl+F or Cmd+F and search for links. or click. as a hostname prefix on the sender's domain. A subdomain wrapping every outbound URL is click tracking.
• Search for img tags with width and height of 1, or an image URL carrying a long random identifier. That is the open pixel.
• Optional confirmation: run a DNS lookup on the suspicious subdomain with dig links.example.com CNAME. A resend-dns.com target tells you which vendor is behind it.

Our step by step guide to detecting tracking pixels in Gmail covers the same method elsewhere. It settles a question about one sender well and is hopeless as a routine, which is the argument for automating the block instead.

How Do You Block Resend Email Tracking in Gmail?

Stop the image request and the open event never happens, because an open only exists if your client fetches the file. Three approaches, with honest tradeoffs.

Turn off automatic image loading. In Gmail, open Settings, See all settings, and under Images choose "Ask before displaying external images". Nothing loads until you approve it, which defeats every open pixel whatever host serves it. The cost is that legitimate images break too, and most people give up within a week.

Run a blocker extension inside Gmail. This is the version people actually keep using, because it requires no decision per message. It also handles the click side, which the Gmail image setting does not touch at all.

Do not click the links. Blunt, but decisive against click tracking. Copy the destination from the source view, or navigate to the site yourself. With Resend this matters more than usual, since the click event is the one carrying your IP address and user agent. Asking for plain text mail helps too where a sender offers it, though few transactional senders do.

Resend Tracker Blockers Compared

No blocker catches everything, and against a sender owned tracking subdomain the differences narrow further.

• Ugly Email. Flags tracked messages with an eye icon in the Gmail list before you open them. An early warning system more than a full stripper.
• PixelBlock. Blocks open pixels and reports what it blocked, but leaves rewritten links alone. With Resend that gap is the important half, because the click carries the device data.
• Trocker. Works across several webmail providers and shows where the pixel sits in the message.
• Proton Mail. Blocks remote content and proxies images by default. Strong protection, but it means moving your email.
• HEY. Ships a spy pixel blocker that names the offending sender. Same tradeoff as Proton: changing providers, not adding a filter.

Gblock sits in the extension category, and its differences are specific rather than sweeping. It runs inside Gmail, so you keep the account and interface you already have. Its blocklist updates automatically, which matters because tracking hostnames appear and disappear as senders configure new subdomains. And it strips tracking links as well as pixels, addressing the half of Resend tracking that carries your IP address and user agent.

The ceiling is worth stating plainly. Any tool that matches known hostnames is weaker against a per sender subdomain than against a shared vendor domain, and Resend's model produces exactly that. Domain blocking is a very good filter. It is not a wall, and anyone telling you otherwise is selling something. Our comparison of Ugly Email, PixelBlock and Trocker and our wider roundup of email tracker blocker extensions map where each option runs out.

What This Means for Your Inbox

Resend deserves credit for a default most competitors do not offer. Off by default, at the domain level, requiring a DNS record to enable, beats the platforms that ship tracking on and bury the toggle. Our writeups on Postmark tracking and Mailgun tracking show how much variation there is across the infrastructure layer alone.

A good default is not a control you hold. The sender decides, you are not told, and nothing in the message announces which way the switch was flipped. In Europe that gap has a legal shape: the EDPB's Guidelines 2/2023 on the technical scope of Article 5(3) of the ePrivacy Directive concluded that a tracking pixel instructs your device to send information to a remote server, which brings it inside the consent requirement. That obligation sits with the sender, and you cannot tell from your inbox who takes it seriously.

So the stance for a Resend heavy inbox is not alarm. Most of your mail from Resend customers is probably untracked, some is not, it looks identical, and the tracked portion learns most from your clicks. The one place you hold real leverage is your own client, before the request leaves your machine. For the surface beyond email, our list of anti tracking browser extensions covers the rest. Loops, another developer focused sending platform, makes the opposite default choice on marketing mail, and its pixel rides a domain that never says Loops: see whether Loops is tracking your email.