Email sending platform comparison
Compare email sending platforms on evidence, not promises
Three distinct sources, never mixed: the reference sheet, what the vendor documents and we verify; the corpus, what we observe in the emails received; the Postmetry analysis, when the two don't agree.
- 63
- sending platforms in the reference sheet
- 21
- capabilities, the same for everyone
- 5301
- emails analyzed
- 0
- cell filled in by deduction
Postmetry reference sheet
What each sending platform allows, capability by capability
21 capabilities across 4 families. Hover over a column to isolate it, click to keep it pinned.
Yes Partially No Not checked — nobody has gone to look yet Not applicable — the question doesn't arise
| Capability Source · check date | Dotdigital none corpus | Klaviyo États-Unis 180 brands corpus | Omnisend 2 brands corpus | Voyado 3 brands corpus |
|---|---|---|---|---|
| Open pixel Vendor documentation | Not verified | Yes | Not verified | Not verified Observed |
| Click tracking Vendor documentation | Yes | Yes | Yes | Not verified Observed |
| Exclusion by campaign Vendor documentation | Not verified | No | Not verified | Non vérifié |
| Exclusion by contact Observed in the tool | Not verified | Yes | Not verified | Not verified |
| Consent — absence means no pixel Observed in the tool | Not verified | Partially | Not verified | Non vérifié |
| Native consent collection Vendor documentation | Non vérifié | Partially | Non vérifié | Non vérifié |
| Tracking anonymization | Not verified | Not verified | Not verified | Non vérifié |
| Traceable choice Observed in the tool | Not verified | Yes | Not verified | Non vérifié |
| List-Unsubscribe | Not verified | Not verified Observed | Not verified | Not verified Observed |
| RFC 8058 — one click | Not verified | Not verified Observed | Not verified | Not verified Observed |
| Preferences page Vendor documentation | Yes | Not verified | Yes | Non vérifié |
| Transactional exceptions Vendor documentation | Not verified | Not verified | Yes | Not verified |
| DKIM Vendor documentation | Not verified | Not verified Observed | Yes | Not verified Observed |
| SPF Vendor documentation | Not verified | Not verified Observed | Yes | Non vérifié Observed |
| DMARC Vendor documentation | Not verified | Not verified Observed | Yes | Non vérifié Observed |
| Sending domain | Not verified | Not verified | Not verified | Not verified |
| Tracking domain Vendor documentation | Partially | Not verified | Not verified | Non vérifié |
| Logging | Not verified | Not verified | Not verified | Non vérifié |
| API Vendor documentation | Not verified | Not verified | Yes | Non vérifié |
| Consent history Vendor documentation | Not verified | Yes | Not verified | Not verified |
| Granularity of settings Vendor documentation | Not verified | Yes | Not verified | Non vérifié |
| Vendor | Non vérifié | Klaviyo | Non vérifié | Non vérifié |
| Headquarters country | Non vérifié | États-Unis | Non vérifié | Non vérifié |
| Data regions | Non vérifié | Selon contrat | Non vérifié | Non vérifié |
| Sheet last reviewed on | 16/08/2026 | 17/10/2026 | 16/08/2026 | Non vérifié |
Postmetry corpus
Observed in our corpus
What brands actually send with these sending platforms. Nothing from the reference sheet here: only what has arrived in an inbox, from addresses we control.
- 666
- brands observed
- 5301
- messages
- 10/31/2026
- last message
Open pixel loaded
share of received messages that embed a tracking image
1 406 messages out of 1 435
RFC 8058 declared
share of messages that declare one-click unsubscribing
1 422 messages out of 1 435
List-Unsubscribe present
share of messages carrying the header
1 422 messages out of 1 435
Brand's tracking domain
share of tracked emails whose domain belongs to the brand
0 messages out of 1 392
1 sending platform in this family has not yet sent any message into the corpus, so it does not appear in these bars : Dotdigital.
Observed below the threshold of 30 messages and 8 brands, so with no published rate : Omnisend (52 messages, 2 brands), Voyado (53 messages, 3 brands).
The market
What professionals search for
Search interest is not a measure of quality or market share.
Google Trends — worldwide, 10/2021 → 09/2026. Relative index from 0 to 100 over the period, calculated by Google for these sending platforms together, on a single scale, whatever segment is chosen above. Export uploaded by hand, no request made from this page.
Hover over a line or a name to isolate it, click to hide it.
What the compared capabilities mean
- Open pixel
- An individualized remote image, loaded when the message is opened. The capability says the platform knows how to insert one — not that it does so on every email.
- Click tracking
- The rewriting of links to count clicks. A treatment of the same nature as the pixel — individualized tracking — and enabled by default on every sending platform.
- Exclusion by campaign
- Sending a given campaign without inserting the open pixel.
- Exclusion by contact
- Removing the pixel for certain recipients only, while still sending them the message.
- Consent — absence means no pixel
- Without recorded consent, the platform knows how to send the message without a pixel. It's the capability that decides.
- Native consent collection
- The platform collects consent to tracking through its own means — a form, a preference centre, a revocation link — and applies it to the email. Exposing an attribute that the brand fills in elsewhere doesn't count as collecting it.
- Tracking anonymization
- A mode advertised as “identifier-free.” It only holds if it stops loading an individualized image: Article 82 concerns access to the terminal, not what is collected afterwards.
- Traceable choice
- A field or mechanism that durably retains the contact's choice on open tracking, and that can be exported.
- List-Unsubscribe
- The header that declares an unsubscribe address or page to the email client.
- RFC 8058 — one click
- One-click unsubscribing, handled by the email client without opening a page.
- Preferences page
- A page where the recipient chooses what they receive, instead of cutting everything off or keeping it all.
- Transactional exceptions
- Excluding a service flow from commercial unsubscribe rules, without taking it out of the logs.
- DKIM
- The signing of the message by the sending domain. It's this signature that carries the selector we use to recognize the platform.
- SPF
- The authorization, published in DNS, for this platform to send on behalf of the domain.
- DMARC
- The alignment of the previous two with the domain visible to the recipient. The policy remains under the brand's control.
- Sending domain
- A brand's own domain in place of the platform's. Once configured, only the DKIM selector still gives the tool away.
- Tracking domain
- A brand's own CNAME for rewritten links and the pixel. Without it, every click from the recipient names the platform.
- Logging
- A dated, exportable log of setting changes. It's what answers the question the day someone asks since when.
- API
- A documented public interface, including for contact attributes — without which a recorded choice stays locked inside the tool.
- Consent history
- The retention of a contact's successive consent states, and their export.
- Granularity of settings
- The level at which a setting applies: account, list, campaign, contact.
- The five states
- Yes, No, Partially, Not verified — nobody has checked yet — and Not applicable, when the question does not arise for this service.
After the grid
Understanding these results
A cell says what the tool allows, never what a brand has done with it. A sending platform that can turn the pixel off says nothing about the brands that did — a brand's report answers that.
How we document sending platforms
Sources, verification dates, confidence levels, and what triggers a review. The same method as for measurements: what has not been observed is not written.
Which sending platform sends your emails?
It is read from the headers, not from a declaration. The report names it, and says where the findings are adjusted with that vendor.