Is SendGrid Tracking Your Email? How to Block It

Every time a company sends you an email through Twilio SendGrid — your Airbnb booking confirmation, your Uber receipt, your Spotify newsletter — an invisible 1x1 pixel quietly phones home the moment you open it. SendGrid processes over 205 billion emails per month across 80,000+ companies worldwide, which means this infrastructure is behind a significant fraction of the email in your inbox right now. Most recipients have no idea it is happening.

Key Takeaways

• SendGrid processes over 205 billion emails per month and is used by Airbnb, Uber, Spotify, Glassdoor, LinkedIn, and Shopify.
• Open tracking embeds a 1x1 transparent pixel at the end of every tracked email, collecting your timestamp, IP address, device, and approximate location on open.
• Click tracking rewrites every link in the email — up to 1,000 links per message — to route through SendGrid's servers before redirecting to the destination, logging your IP on each click.
• SendGrid's "Link Branding" feature lets senders replace sendgrid.net URLs with their own subdomain (e.g., click.company.com), making standard blocklists ineffective.
• Gmail's image proxy shields your IP from pixel fires but provides zero protection for click tracking, where your real IP address is fully exposed.

What Is SendGrid and Why Does It Matter?

SendGrid is the world's largest cloud-based email delivery platform, now owned by Twilio. It sits between companies and their recipients, handling the technical work of ensuring emails actually arrive. Transactional emails — password resets, order confirmations, shipping updates — and marketing campaigns both run through its infrastructure.

The scale matters because it concentrates tracking across an enormous slice of everyday email. Unlike a dedicated sales tool such as HubSpot or Yesware that targets specific sales workflows, SendGrid powers everything from routine notifications to mass marketing campaigns. You cannot reasonably avoid it by filtering sender types. For a broader look at how email tracking software operates across different platforms, see What Is Email Tracking Software? How to Block It.

How Does SendGrid Open Tracking Work?

SendGrid open tracking adds a transparent 1x1 pixel image to the end of every tracked email. When your email client loads the email and renders its images, it fires an HTTP GET request to SendGrid's servers to fetch that image — and SendGrid logs an open event.

According to SendGrid's own documentation, the data collected at open includes:

• Timestamp — the exact date and time you opened the email
• IP address — used to infer your approximate city, region, and country
• User agent — which email client and device you are using

SendGrid distinguishes between a "unique open" (first time you open a specific email) and an "open" (every subsequent time). Both are tracked and reported to the sender. Open tracking is enabled by default in SendGrid's Marketing Campaigns product. Senders have to deliberately turn it off via Settings → Tracking → Open Tracking — recipients have no control over this at all.

How Does SendGrid Click Tracking Work?

Click tracking rewrites every hyperlink in the email before delivery, replacing your destination URL with a SendGrid tracking URL. Per SendGrid's documentation, this rewriting applies to up to 1,000 links per email.

A link that originally pointed to https://example.com/offer arrives in your inbox looking something like:

https://click.sendgrid.net/ls/click?upn=[encoded-data]

When you click that link, your browser first hits SendGrid's servers, which log the click event — recording your IP address, the URL you clicked, a timestamp, and your device — before instantly redirecting you to the actual destination. This is significant because click tracking bypasses Gmail's image proxy entirely. Your real IP address hits SendGrid's servers the moment you click anything.

What Is SendGrid Link Branding — and Why Does It Break Blocklists?

Link Branding lets senders replace the default click.sendgrid.net tracking domain with their own custom subdomain. A company can configure click.example.com to point to SendGrid's infrastructure, so every tracked link routes through that branded subdomain rather than anything that says "sendgrid" in the URL.

This breaks blocklists that filter on sendgrid.net domains. If Airbnb has configured click.airbnb.com as its SendGrid branded domain, tracking links in Airbnb emails contain no reference to SendGrid at all. You cannot spot them by hovering over a link. This is the same evasion dynamic described in The Tracking Pixel Isn't Dead — It Just Learned to Dodge Gmail, where tracking infrastructure increasingly hides behind first party looking domains to escape blocklists.

Does Gmail's Image Proxy Protect You From SendGrid Tracking?

Gmail's image proxy partially protects you — but only for open tracking, not click tracking.

Since 2013, Gmail has routed all email images through Google's own proxy servers. When SendGrid's tracking pixel fires, the HTTP request reaches Google's infrastructure, not your device directly. Google's IP address is logged instead of yours, which masks your real location and device from the open event.

But the proxy has hard limits: it only intercepts image loads, not link clicks. Gmail's proxy can also pre-fetch images at delivery time, which may register a false open in SendGrid even before you have read the email. Every link click sends your real IP directly to SendGrid's servers regardless of the proxy. For a full breakdown, see Email Tracking Has Outgrown the Pixel (2026).

How Can You Tell If an Email Was Sent Through SendGrid?

You can check the raw source of any email in Gmail. Open the email, click the three-dot menu in the top right, and select "Show original." Then look for:

• X-Mailer: SendGrid or X-SG-EID in the email headers
• sendgrid.net anywhere in the HTML body, in image src attributes or link href values
• click.sendgrid.net in rewritten link URLs — the default click tracking domain
• Custom branded subdomains like click.company.com pointing away from the real destination — these may indicate Link Branding

This manual inspection is informative but not practical for every email you receive. A purpose-built blocker handles it automatically.

Why Recipients Should Care

The combination of open tracking and click tracking in SendGrid emails creates a behavioral profile that most recipients never consent to. You open a shipping notification — SendGrid logs your timestamp and approximate location. You click the tracking link — SendGrid logs your real IP, the exact link, and the time. Across dozens of emails from different senders all using the same underlying infrastructure, this adds up to a granular map of your habits, schedule, and location over time.

SendGrid's scale multiplies this effect. The emails affected are not just promotional — they include transactional messages you need to receive: receipts, booking confirmations, account alerts. You cannot opt out of receiving them without opting out of the service entirely.

Under GDPR and CCPA, tracking recipients without consent is increasingly restricted. SendGrid's own documentation acknowledges this, placing the compliance burden on senders rather than the platform. But as a recipient, you have no visibility into whether a given sender has obtained lawful consent for tracking you. The default is surveillance; the burden of reversal falls on the recipient.

How to Block SendGrid Email Tracking

Three approaches exist, ordered by effectiveness:

1. Use Gblock (most effective). Gblock is a Chrome extension that blocks tracking pixels in Gmail before they fire. It intercepts image load requests — including SendGrid's 1x1 open tracking pixel — so the pixel never reaches SendGrid's servers and no open event is recorded. Critically, Gblock handles custom branded domains too, using behavioral pattern matching rather than simple domain lists. It also flags tracked links before you click, covering both open tracking and click tracking together.

2. Disable remote images in Gmail. Go to Gmail Settings → General → Images → "Ask before displaying external images." This prevents automatic pixel fires on open. The drawbacks are significant: every email loses inline images until you manually approve them, and it does nothing for click tracking. You remain fully exposed every time you click a link.

3. Read emails in plain text. In Gmail, view any email as plain text via the three-dot menu → "View as plain text." Plain text strips HTML entirely, removing the pixel. This blocks open tracking but does not protect you from click tracking if you then click any link, and it degrades the display of every email regardless of whether it is tracked.

Of these options, only Gblock covers both tracking vectors — including Link Branding — without breaking your email experience. For a full comparison of blocking tools, see How to Block Email Tracking in Gmail (2026 Comparison) and Best Email Tracker Blocker Extensions (2026).