Signature365 email provider statistics and deliverability context
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According to Live Direct Marketing's daily Tranco top-1M scan (September 24, 2026), Signature365 is the email service provider (ESP) for 136 domains — 0.02% of 637,420 SPF-publishing domains. Its strongest TLD is .com (40.4% of its domains). Detection: include: mechanisms in the SPF record.
Last updated from the 2026-09-24 DNS snapshot.
What Signature365 represents in this dataset
Signature365 — email signature management.
Directory category: Gateway. The classification comes from include: mechanisms in the SPF record. It describes observed DNS infrastructure, not a commercial relationship and not the placement of any individual message.
What the 2026-09-24 snapshot shows about Signature365
Across 21 distinct TLDs its top three are .com (40.4%), .de (10.3%), .nl (9.6%) — together 60.3% of the 136 domains, which makes the footprint moderately concentrated, with a recognisable home market. The service most often observed on the same domains is Microsoft 365 (Mailbox, 100 domains, 73.5% of them), followed by Unknown / Other (5.9%). Directly comparable by the same detection rule: Amazon SES, SendGrid (Twilio), Mailgun. Ranking between them reflects what is published in DNS, not delivery quality or volume sent. All figures come from a single daily DNS snapshot (2026-09-24); a domain appears here when its published records match the include: mechanisms in the SPF record rule, which is an infrastructure fact, not a commercial relationship.
Commonly used together with Signature365
What else the same 136 domains use — cross-tabulated from the same daily snapshot (2026-09-24).
| Type | Service | Domains | Share of Signature365 users |
|---|---|---|---|
| Mailbox | Microsoft 365 | 100 | 73.5% |
| Mailbox | Unknown / Other | 8 | 5.9% |
| Mailbox | Hornetsecurity | 6 | 4.4% |
| Mailbox | Proofpoint | 3 | 2.2% |
| Mailbox | Cisco IronPort | 3 | 2.2% |
| Mailbox | Self-Hosted | 3 | 2.2% |
| ESP | Mailchimp | 15 | 11.0% |
| ESP | Mailjet (Sinch) | 14 | 10.3% |
| ESP | Zendesk | 14 | 10.3% |
| ESP | HubSpot | 14 | 10.3% |
TLD distribution (top 21 of 21)
Frequently asked questions
How many domains use Signature365?
136 domains in the Tranco top-1M use Signature365 as their email service provider (ESP) as of September 24, 2026, according to Live Direct Marketing's daily DNS scan.
What is Signature365's market share?
Signature365 holds 0.02% of SPF-publishing domains in the Tranco top-1M (snapshot of 2026-09-24). The number is recomputed every day.
What are the biggest alternatives to Signature365?
The largest email service provider (ESP)s in the same category by Tranco top-1M share are: Amazon SES, SendGrid (Twilio), Mailgun, Zendesk, Mailchimp (as of 2026-09-24).
Largest email service provider (ESP)s in this category
Amazon SES (6.23%) · SendGrid (Twilio) (4.68%) · Mailgun (4.01%) · Zendesk (3.77%) · Mailchimp (3.61%) · Mandrill (3.26%) · HubSpot (3.18%) · Salesforce (2.57%) · Mailjet (Sinch) (2.14%) · Cloudflare Email Routing (1.96%)
Domain sample (top 100 by Tranco rank)
Showing 100 of 136 domains.