Letsignit email service provider (ESP)
According to Live Direct Marketing's daily Tranco top-1M scan (September 12, 2026), Letsignit is the email service provider (ESP) for 150 domains — 0.02% of 629,828 SPF-publishing domains. Detection method: include: mechanisms in the SPF record.
Key facts
- 150 domains in the Tranco top-1M use Letsignit (0.02% of SPF-publishing domains).
- Snapshot date: 2026-09-12 — recomputed every day.
- Strongest TLD: .com (52.0% of its domains).
- Most co-used service: Microsoft 365.
- Directory category: email security gateway.
Why Letsignit appears in this category
Letsignit — email signature management.
We classify it as a email security gateway 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.
Letsignit is an email signature management service that organisations use to standardise and control email signatures, branding, and compliance metadata across their mail systems. When deployed, it authenticates via SPF include mechanisms in the sending domain's DNS records.
Letsignit's footprint is concentrated among smaller organisations in the .com domain space, typically deployed alongside Microsoft 365. For mail administrators, this pattern means Letsignit represents a straightforward SPF configuration addition with no major reputation implications.
Where Letsignit 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 | 14 | 9.3% |
| Top 1,000,000 | 134 | 89.3% |
| Unranked | 2 | 1.3% |
Top-level domain split
| TLD | Domains | Share | |
|---|---|---|---|
| .com | 78 | 52.0% | |
| .fr | 33 | 22.0% | |
| .org | 8 | 5.3% | |
| .nl | 4 | 2.7% | |
| .se | 3 | 2.0% | |
| .net | 3 | 2.0% | |
| .io | 3 | 2.0% | |
| .cl | 2 | 1.3% | |
| .dk | 2 | 1.3% | |
| .co.uk | 2 | 1.3% |
What Letsignit users also use
Cross-tabulated from the same daily snapshot — the other email services seen on the same 150 domains.
| Type | Service | Domains | Share of Letsignit users |
|---|---|---|---|
| Mailbox | Microsoft 365 | 108 | 72.0% |
| Mailbox | Unknown / Other | 7 | 4.7% |
| Mailbox | Sophos Email | 7 | 4.7% |
| Mailbox | Self-Hosted | 5 | 3.3% |
| Mailbox | Proofpoint | 4 | 2.7% |
| Mailbox | Google Workspace | 3 | 2.0% |
| ESP | Brevo (ex-Sendinblue) | 33 | 22.0% |
| ESP | Mailjet (Sinch) | 30 | 20.0% |
| ESP | Salesforce | 15 | 10.0% |
| ESP | SendGrid (Twilio) | 13 | 8.7% |
SPF authentication and signature-management platforms
Letsignit uses SPF includes to authenticate, adding a single DNS mechanism to the sender's SPF record rather than operating independent sending infrastructure. Because the service is concentrated among smaller organisations and deployed primarily as an add-on to Microsoft 365, it does not accumulate the high-volume reputation concerns that larger mail platforms might carry, making it a straightforward authentication component for organisations that use it.
See the full Letsignit data page (KPI cards, trend, sample domains) →
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Frequently asked questions
Does Letsignit appear in my mail authentication records, and is it a deliverability concern?
Letsignit is a signature management platform that adds an SPF include to your domain's DNS records. Because it operates primarily among smaller organisations, it represents a routine configuration element rather than a reputation risk.
How many domains use Letsignit?
150 domains in the Tranco top-1M use Letsignit as their email service provider (ESP) as of September 12, 2026 (0.02% of SPF-publishing domains), according to Live Direct Marketing's daily DNS scan.
Is Letsignit common enough to affect email deliverability testing?
Letsignit 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 Letsignit most?
Letsignit's largest TLD is .com (52.0% of its domains); it appears across 21 TLDs in total.