PostmarkOpen-tracking pixel, click tracking and unsubscribe
Postmark can insert an open-tracking pixel; removing it campaign by campaign is only partly possible.
API / Transactionnel · ActiveCampaign · vendor's site ↗ · code postmark
API-based sending service, aimed at developers and specialized in transactional email. It was acquired by ActiveCampaign in 2022.
Postmetry reference sheet
What the vendor says, checked by us
7 sources · last reviewed on 08/19/2026. Still not checked: Exclusion by contact, Tracking anonymization, List-Unsubscribe, RFC 8058 — one click, Preferences page, SPF, Sending domain, Logging, Consent history.
Postmetry corpus
What brands actually send
6 messages received from 10/07/2026 to 10/14/2026. Below the threshold of 30 messages and 8 brands: no rate is published.
Postmetry reference sheet
What this ESP allows
Catalog shared by both pages. Each note carries its source, its date, and its confidence level.
On the right, what our emails say about it: matching, contradicted, never observed despite the volume, too few emails to conclude — or out of reach, when the capability can't be read from an email.
Tracking 2 not met · 1 partial · 3 not verified
Open pixel Yes 1 note · 19/08/2026 Too few emails seen on 2 of 2 emails from 1 brand, 1 months
The default value of TrackOpens is false, so if it is not present
Caveat Opt-in: without the TrackOpens field (API) or the X-PM-TrackOpens header (SMTP), no pixel is inserted. A 1x1 pixel on HTML only, open data kept for 45 days. The opposite of every marketing sending platform we reference.
Tracking opens per email · API documentation · last reviewed on 08/19/2026 · confidence high
Click tracking Yes 1 note · 19/08/2026 Too few emails out of 2 emails from 1 brand, 1 months
links in your messages will be replaced with new links that route through
Caveat Disabled by default (TrackLinks=None documented as the default for all servers); when enabled, rewriting via click.pstmrk.it over permanent HTTPS, links that never expire (even after the Postmark server is deleted), and the account is subject to approval before any tracking.
Tracking links · API documentation · last reviewed on 08/19/2026 · confidence high
Exclusion by campaign Partially 1 note · 04/08/2026 Out of reach
A costly quirk: tracking enabled at server level can **force** tracking, even when a message explicitly asks for the opposite. A per-message setting that a global setting can override is not a per-campaign exclusion — hence "partial".
Observations in the interface, first batch · Help centre · last reviewed on 08/04/2026 · confidence medium
Unsubscribe 3 not verified
Transactional exceptions Yes 1 note · 19/08/2026
transactional and broadcast messages travel on different IP infrastructure
Caveat Message Streams: transactional/broadcast separation down to the IP infrastructure, with UnsubscribeHandlingType per stream ("Postmark" on broadcasts, "none" possible on transactional — Message Streams API). The most structural model among the tools we reference.
Introduction · API documentation · last reviewed on 08/19/2026 · confidence high
Authentication 1 partial · 2 not verified
DKIM Yes 1 note · 19/08/2026 Too few emails seen on 6 of 6 emails from 4 brands, 1 months
You will then see generated DKIM and Return-Path records for this domain
Caveat DKIM plus a custom Return-Path (CNAME) generated at domain verification — the custom Return-Path carries SPF alignment. The ecosystem describes a timestamped selector ([timestamp]pm._domainkey), not admissible here: to be observed in our corpus.
Postmark Manual · Help centre · last reviewed on 08/19/2026 · confidence medium
DMARC Yes 1 note · 19/08/2026 Too few emails seen on 5 of 6 emails from 4 brands, 1 months
Convert all known email sources to have DMARC aligned with DKIM and SPF.
Caveat The manual guides a gradual progression none → quarantine → reject, and Postmark publishes its own DMARC monitoring tool. Policy at the brand's discretion.
Postmark Manual · Help centre · last reviewed on 08/19/2026 · confidence medium
Tracking domain Partially 1 note · 19/08/2026 Too few emails out of 2 emails from 1 brand, 1 months
The tracking domain that the user will see is click.pstmrk.it.
Caveat A vendor tracking domain shown to recipients (click.pstmrk.it) — direct data for esp_signatures. A custom domain is not documented on the pages read.
Tracking links · API documentation · last reviewed on 08/19/2026 · confidence high
Infrastructure & governance 2 not verified
API Yes 1 note · 19/08/2026 Out of reach
just set the json parameter "TrackOpens: true" in the API
Caveat The API controls tracking per message and exposes events (webhooks); there is no contact database at Postmark (suppression lists only), so no contact attributes to control.
Open tracking is (finally) here! · Vendor blog · last reviewed on 08/19/2026 · confidence low
Granularity of settings Yes 1 note · 19/08/2026 Out of reach
an individual message can still be tracked with the Postmark API
Caveat The second precedence rule among the tools we reference, and it is asymmetric: server OFF + message ON ⇒ tracked (the message can enable it); server ON ⇒ a message's TrackOpens=false is overridden (developer doc tracking-opens-per-email: "no way to disable open tracking on a per-email basis when the server's setting is enabled"). Any activation prevails — the exact opposite of a consent model, to be compared with the Customer.io rule (workspace OFF prevails).
How do I enable open tracking? · Help centre · last reviewed on 08/19/2026 · confidence medium
Postmetry corpus
Observed in our corpus
Recorded by our analyzers on messages received on addresses we control. Nothing from the reference sheet here, no access to the tool.
6 messages, 4 brands, below the threshold of 30 messages and 8 brands: no rate is published. A percentage on so few emails, or so few brands, describes what one brand configured, not what the sending platform does.
Period observed
10/2026 → 14/10/2026
1 months, 4 distinct brands.
Identification signals
What we recognized the sending platform by, message by message.
- postmark 100 %
Limits of this analysis
It doesn't say what a brand has actually configured. A sending platform that allows turning off the pixel says nothing about which brands have done so — that's what a brand's report answers.
It doesn't rank. No score, no recommendation: capabilities don't carry the same weight depending on the use, and that weight isn't ours to set.
A “not checked” cell is not a “no”. It says nobody has gone to look yet, and nothing else.
The corpus does not establish a capability. A rate of observed pixels says what brands send, not what the tool can do.
Sources
7 sources- Tracking opens per email API documentation · confidence high 19/08/2026
- Tracking links API documentation · confidence high 19/08/2026
- Postmark Manual Help centre · confidence medium 19/08/2026
- Open tracking is (finally) here! Vendor blog · confidence low 19/08/2026
- Introduction API documentation · confidence high 19/08/2026
- How do I enable open tracking? Help centre · confidence medium 19/08/2026
See the 1 other sources ▾ Collapse ▴
- Observations in the interface, first batch Help centre · confidence medium 04/08/2026
Comparable sending platforms
Compare the whole family →Frequently asked questions
Can you turn off open tracking in Postmark?
Does Postmark rewrite links for click tracking?
Do your emails go through Postmark?
The sending platform is read from the headers, not from a claim. The report names it, and says where to fix the findings with that vendor.