Watermark SaaS sender
According to Live Direct Marketing's daily Tranco top-1M scan (September 20, 2026), Watermark is the SaaS sender for 135 domains — 0.02% of 638,158 SPF-publishing domains. Detection method: include: mechanisms in the SPF record.
Key facts
- 135 domains in the Tranco top-1M use Watermark (0.02% of SPF-publishing domains).
- Snapshot date: 2026-09-20 — recomputed every day.
- Strongest TLD: .edu (89.6% of its domains).
- Most co-used service: Microsoft 365.
- Directory category: SaaS sender.
Why Watermark appears in this category
Watermark Insights — higher-ed assessment cloud.
We classify it as a SaaS sender from include: mechanisms in the SPF record matching a maintained provider rule. This is infrastructure attribution from public DNS, not evidence of a direct contract or exclusive use.
Watermark is a SaaS platform that provides institutional communication and workflow management services, functioning as an email provider for the organisations that use it. Institutions using Watermark authorise its mail servers to send email on their behalf by including Watermark in their SPF records, thereby delegating email delivery infrastructure to Watermark's cloud platform.
Watermark's footprint is concentrated in the education sector, appearing predominantly in .edu domain authorisation records rather than across large commercial brands. It is frequently deployed alongside Microsoft 365 within educational institutions, reflecting the pattern of higher-education organisations adopting multiple cloud platforms in parallel. For senders and recipients alike, Watermark-authenticated email typically signals institutional or educational communication; for anyone managing email reputation, understanding that Watermark serves primarily smaller educational institutions rather than mainstream enterprises shapes realistic expectations for mail volume and sender behaviour patterns.
Where Watermark sits in the Tranco ranking
| Tranco rank band | Domains | Share of its base |
|---|---|---|
| Top 1,000 | 0 | 0.0% |
| Top 10,000 | 0 | 0.0% |
| Top 100,000 | 19 | 14.1% |
| Top 1,000,000 | 115 | 85.2% |
| Unranked | 1 | 0.7% |
Top-level domain split
| TLD | Domains | Share | |
|---|---|---|---|
| .edu | 121 | 89.6% | |
| .no | 3 | 2.2% | |
| .com | 3 | 2.2% | |
| .za | 1 | 0.7% | |
| .ar | 1 | 0.7% | |
| .nz | 1 | 0.7% | |
| .kg | 1 | 0.7% | |
| .us | 1 | 0.7% | |
| .ca | 1 | 0.7% | |
| .de | 1 | 0.7% |
What Watermark users also use
Cross-tabulated from the same daily snapshot — the other email services seen on the same 135 domains.
| Type | Service | Domains | Share of Watermark users |
|---|---|---|---|
| Mailbox | Microsoft 365 | 80 | 59.3% |
| Mailbox | Google Workspace | 29 | 21.5% |
| Mailbox | Barracuda | 8 | 5.9% |
| Mailbox | Proofpoint | 5 | 3.7% |
| Mailbox | Mimecast | 3 | 2.2% |
| Mailbox | Self-Hosted | 3 | 2.2% |
SPF delegation and educational sender reputation
Watermark appears in institutional SPF records as an authorised mail provider, typically via an include mechanism that delegates part of the sender authorisation to Watermark's infrastructure. This means Watermark's own sender reputation—built from the collective behaviour of its users—directly influences deliverability for each institution's outbound mail. Institutions running both Watermark and Microsoft 365 must carefully manage their SPF records to authorise both platforms without exceeding the SPF query limit, and any reputation issues in Watermark's IP space will affect institutional delivery regardless of the individual institution's sending practices.
See the full Watermark data page (KPI cards, trend, sample domains) →
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Frequently asked questions
Why does Watermark appear in my domain's SPF record?
Watermark is an email delivery platform used by educational institutions to send mail on their behalf; institutions add Watermark to their SPF records to authorise Watermark's servers as legitimate senders. This delegation allows institutions to leverage Watermark's infrastructure and sender reputation rather than managing their own outbound mail servers.
How many domains use Watermark?
135 domains in the Tranco top-1M use Watermark as their SaaS sender as of September 20, 2026 (0.02% of SPF-publishing domains), according to Live Direct Marketing's daily DNS scan.
Is Watermark common enough to affect email deliverability testing?
Watermark accounts for 0.02% of SPF-publishing domains in the top 1M. Whether you should seed a test mailbox there depends on how much of your audience it represents — the co-usage table above shows the services it appears alongside most.
Which countries or TLDs use Watermark most?
Watermark's largest TLD is .edu (89.6% of its domains); it appears across 11 TLDs in total.