Is Acoustic Tracking Your Email? How to Block It

Acoustic email tracking is unusual in one respect. Most platforms in this series hide behind branded subdomains, so nothing looks odd. Acoustic Campaign, by default, does the opposite: its links sit on numbered domains carrying no branding at all, which sends people straight to a search engine asking what mkt1234.com is. The answer runs back through IBM to a company called Silverpop that stopped existing under that name in 2014.

Key Takeaways

• Acoustic's custom email domain documentation uses abc.mkt1234.com as its example of a default, unbranded Campaign domain, and separately states that pages1.net represents Acoustic Campaign for landing pages.
• Acoustic Campaign uses a 1x1 pixel to determine whether a message was opened, and the sender picks one of four tracking levels from Unique down to No Tracking.
• Every link Acoustic rewrites carries spMailingID, spUserID, spJobID and spReportId; spUserID identifies the individual contact record.
• Acoustic's raw event export returns event type, timestamp, email address and mailing identifiers, but publishes no field for IP address, device, operating system, email client or geolocation.
• Acoustic's web tracking opt-in prompt appears only if the marketer installs it, covers website tracking only, and does nothing about the open pixel in the message.

What Is mkt1234.com and Why Is It in My Inbox?

It is the shape of a default Acoustic Campaign tracking domain, and Acoustic uses that exact string as its example. A support article on required updates for custom email domains tells administrators to check their domain settings: "If all listings in the view are similar to abc.mkt1234.com, no action is needed." A numbered mkt domain is what you get when the sender has not paid for branding.

The same article says what branding buys: "A custom domain brands the hover links that you include in an email." Skip it, and the platform's numbering shows in every message.

Wikimedia engineers documented their fundraising setup in Phabricator task T114010, noting that "Silverpop tracks clicks by sending the recipient to links.wikimedia.mkt4477.com, which captures a few pieces of data and then quickly redirects the donor." Different number, same family, and the donor never sees wikimedia.org.

Ghostery's WhoTracksMe attributes eight domains to Silverpop: mkt51.net, mkt912.com, mkt922.com, mkt941.com, pages01.net, pages02.net, pages04.net and pages05.net. Acoustic confirms the second half independently: "pages1.net" represents Acoustic Campaign.

One honest limit: no master list of mkt numbers is published. Treat a hostname shaped like something.mktNNNN.com or pagesNN.net as a strong indicator, not proof.

Why Do the Domains Look Nothing Like the Brand?

Because the infrastructure predates the brand by two decades. Silverpop was founded in Atlanta in 1999 and sold its email platform, Engage, for fifteen years. IBM bought it in 2014 and folded it into Watson Marketing, then sold that division to Centerbridge Partners in 2019, which relaunched it as Acoustic. The product mailing you is Acoustic Campaign, formerly IBM Watson Campaign Automation, formerly Silverpop Engage.

Three owners, three names, and the domains never moved. Traces sit in current documentation. Acoustic's web tracking guide tells customers to look in their browser for a cookie named com.silverpop.iMAWebCookie. The custom domain article tells IT teams to run dig +trace and look for silverpop.com in the nameserver records. Which is why searching a strange mkt domain turns up a company absorbed twelve years ago, and why the natural conclusion, that the mail is fraudulent, is usually wrong.

Does Acoustic Campaign Use an Open Tracking Pixel?

Yes. Acoustic's documentation on email settings states: "Campaign uses a 1x1 pixel that is placed in emails to determine whether it was opened. If images aren't viewed by the recipient, because they either block all images or receive a text-only email, then the tracking pixel isn't triggered and the email isn't tracked."

That last clause is the whole defence, stated by the vendor. No image fetch, no open. The same page lists four tracking levels:

• Unique tracks everything down to the individual email address: opens, clicks, forwards and subscribes.
• Aggregate collects grand totals only.
• Opens Only records which mailings were opened.
• No Tracking records bounces and nothing else.

You cannot tell from your inbox which one a sender picked. Our walkthrough on detecting tracking pixels in Gmail shows how to check a specific message yourself.

What Does an Acoustic Open Report Back?

Less than you might expect, which is worth saying rather than inflating. The developer reference for RawRecipientDataExport, the API that hands a sender their contact level events, documents columns for recipient ID, recipient type, mailing ID, report ID, campaign ID, email address, event type and event timestamp, plus optional body type, click name, destination URL and conversion detail.

No IP address column. No device, no operating system, no email client, no city. The documented open record is this person, this message, this moment.

Two caveats stop that being reassuring. Absence from an export schema is not absence from a server log, since fetching a remote image hands over your IP address and user agent regardless. And a timestamp gets revealing once it repeats weekly. Set it beside what Litmus reports through emltrk.com, which returns your city, your coordinates and your reading time, and Acoustic's pixel looks restrained. The interesting part of Acoustic is the click.

What Happens When You Click an Acoustic Link?

You are identified to the destination site by parameters Acoustic appends automatically. Its article on tracking IDs for qualified domains shows the format:

https://www.domain.com/?spMailingID=1234567890&spUserID={encoded-value}&spJobID=1234567890&spReportId={encoded-value}

• spMailingID identifies the mailing.
• spUserID identifies the unique Acoustic contact record, which is to say you.
• spReportId identifies the report, keeping recurring sends separable.
• spJobID covers bounce or retry sends, often matching spReportId.

Those identifiers then meet the web tracking script on the site. Acoustic's documentation describes a webSyncID, "a unique identifier for each visitor to your tracked sites," stored in a first party cookie, and says the code "automatically rewrites URLs to include tracking identifiers when visitors click from one tracked website to another." Arriving by email link adds four session cookies, listed in the web tracking opt-in article: com.silverpop.iMA.mid, .uid, .jid and .rid, holding the mailing, recipient, job and report IDs of the email that produced the visit.

One click carries your contact ID into a cookie that follows you across every page the sender tracks. The pixel produces a row; the click produces a session. Our guide to email link wrapping and click tracking covers the general pattern.

Can You Opt Out of Acoustic Tracking?

Not as a recipient, no. Acoustic ships an opt-in mechanism, and its documentation shows how narrow that is.

It is a prompt the marketer must install, by adding <meta name='com.goacoustic.webtrackingoptin' content='true'/> to every tracked page alongside the request code. If a visitor refuses, Acoustic states the system does not track web activity "except for 'submit' events on landing pages."

Three gaps. The prompt exists only where a marketer added it. It governs website tracking, not the pixel in the message. Landing page form submissions are tracked regardless. Unsubscribing stops one sender's mail and nobody else's. France's CNIL now treats email pixels as trackers requiring prior consent, covered in our piece on the CNIL pixel recommendation and its deadline. Elsewhere the control sits on your side of the wire or nowhere.

How Do You Block Acoustic Email Tracking in Gmail?

Four steps, in rough order of effort.

1. Stop Gmail loading images automatically. Open Gmail, click the gear icon, choose See all settings, then under General find Images and select "Ask before displaying external images". By Acoustic's own description an unviewed image triggers no pixel, so this is decisive. It also breaks every legitimate image, which is why most people switch it back within a week.

2. Check the source. In Gmail on desktop, use the three dot menu, choose Show original, and search the raw text for spUserID, mkt or pages1.net. Hits inside link targets mean your clicks are attributed to you.

3. Do not follow the link as written. Copy the link address, delete everything from the question mark onward, paste the clean URL. Better still, navigate to the site yourself. The click is the identifying event, so this habit removes the most tracking, and it is the least sustainable on a phone.

4. Install a blocker that handles both halves. Pixels and rewritten links are separate problems and most tools solve one. Our step by step on blocking email tracking in Gmail covers the setup.

Which Blocker Actually Covers This?

Several tools do a real job. Here is where each stops.

• PixelBlock blocks open pixels in Gmail and marks each with a red eye. Pixel focused, so Acoustic links still carry spUserID.
• Ugly Email flags tracked messages in the inbox list before you open them. Detection leans on known senders and services.
• Trocker marks both pixels and tracked links, across Gmail, Outlook and Yahoo.
• Proton Mail blocks remote content by default and proxies images, killing opens at the mailbox. Requires moving your mail, and click parameters still fire.
• HEY screens senders and strips spy pixels, reporting who tried. Again, a change of provider.

Gblock sits beside the first three and differs in three ways that matter here. Its blocklist updates automatically, which counts when the domain family is numbered and obscure rather than one famous host. It strips tracking parameters from links, so the sp identifiers never reach the sender's site. And it stays inside Gmail.

No extension promises complete coverage. A sender who pays for a branded custom domain defeats recognition by design, which is what Acoustic sells that feature for, and nothing protects you once you fill in a landing page form. We put the options side by side in our roundup of email tracker blocker Chrome extensions.

What This Means for Your Inbox

Acoustic Campaign is enterprise software, so you never chose it and probably cannot name a company running on it. You just get the mail: the airline statement, the bank newsletter, the charity appeal. Wikimedia is the instructive case, a nonprofit most people trust routing donors through a hostname with a four digit number in it.

The takeaway is not that Acoustic is worse than its rivals; on its own documentation the open record is thinner. It is that platform age has consequences you feel in the inbox. A stack built in 1999, sold twice and renamed three times still routes your clicks through domains named after a company that no longer exists, and still offers you no switch. Turn off automatic image loading if you can live with it, treat every marketing link as a redirect that knows your name, and put something in the browser that strips the identifiers first. Our comparison of the best email tracker blocker extensions is the place to start.