DynDNS Mailhop email service provider (ESP)
According to Live Direct Marketing's daily Tranco top-1M scan (September 20, 2026), DynDNS Mailhop is the email service provider (ESP) for 192 domains — 0.03% of 638,158 SPF-publishing domains. Detection method: include: mechanisms in the SPF record.
Key facts
- 192 domains in the Tranco top-1M use DynDNS Mailhop (0.03% of SPF-publishing domains).
- Snapshot date: 2026-09-20 — recomputed every day.
- Strongest TLD: .com (49.5% of its domains).
- Most co-used service: Microsoft 365.
- Directory category: email forwarding service.
Why DynDNS Mailhop appears in this category
Dyn Mailhop — email forwarder/relay.
We classify it as a email forwarding service 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.
DynDNS Mailhop is an email relay service operated by DynDNS, a company historically known for dynamic DNS hosting. Mailhop provides message relay functionality for organisations that explicitly authorise it via SPF records, enabling it to handle transmission of outbound or relayed mail.
Mailhop's infrastructure footprint is concentrated in smaller sites and organisations operating legacy or shared mail arrangements, predominantly in the .com domain space. Its frequent co-appearance with Microsoft 365 in SPF records suggests it often serves as a supplementary relay for organisations whose primary email platform is M365 but which require external relay capacity or integration with legacy mail systems.
Where DynDNS Mailhop sits in the Tranco ranking
| Tranco rank band | Domains | Share of its base |
|---|---|---|
| Top 1,000 | 2 | 1.0% |
| Top 10,000 | 1 | 0.5% |
| Top 100,000 | 12 | 6.2% |
| Top 1,000,000 | 174 | 90.6% |
| Unranked | 3 | 1.6% |
Top-level domain split
| TLD | Domains | Share | |
|---|---|---|---|
| .com | 95 | 49.5% | |
| .org | 23 | 12.0% | |
| .net | 16 | 8.3% | |
| .co.uk | 6 | 3.1% | |
| .com.au | 4 | 2.1% | |
| .cl | 4 | 2.1% | |
| .co.za | 3 | 1.6% | |
| .ch | 2 | 1.0% | |
| .se | 2 | 1.0% | |
| .com.mx | 2 | 1.0% |
What DynDNS Mailhop users also use
Cross-tabulated from the same daily snapshot — the other email services seen on the same 192 domains.
| Type | Service | Domains | Share of DynDNS Mailhop users |
|---|---|---|---|
| Mailbox | Microsoft 365 | 61 | 31.8% |
| Mailbox | Self-Hosted | 35 | 18.2% |
| Mailbox | Unknown / Other | 34 | 17.7% |
| Mailbox | Google Workspace | 16 | 8.3% |
| Mailbox | Barracuda | 9 | 4.7% |
| Mailbox | Generic / unmatched (mx*.*) | 7 | 3.6% |
| ESP | SendGrid (Twilio) | 16 | 8.3% |
| ESP | Amazon SES | 15 | 7.8% |
| ESP | Zendesk | 11 | 5.7% |
| ESP | HubSpot | 10 | 5.2% |
Coexistence with Microsoft 365 ecosystems
Mailhop frequently appears in the mail infrastructure of organisations already committed to Microsoft 365. This architectural pattern—M365 as primary platform plus Mailhop as external relay—suggests organisations using it for specific mail flows that fall outside their M365 tenancy, legacy application integrations that predate their Microsoft migration, or particular sending paths that require independent relay handling. Because Mailhop operates at smaller scale than mainstream ESPs, organisations routing mail through it should monitor its reputation status independently; poor reputation assigned to Mailhop infrastructure affects all downstream senders relying on it, but equally, its smaller deployment footprint can mean it avoids the filtering challenges that accumulate at large shared services.
See the full DynDNS Mailhop data page (KPI cards, trend, sample domains) →
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Frequently asked questions
Should I test email deliverability against DynDNS Mailhop?
Test against Mailhop only if you are directly routing mail through it or investigating a sender that does—that is, if Mailhop appears in the relevant SPF record. For general deliverability monitoring, its smaller footprint means it affects only a niche subset of mail flows, so it is rarely a priority testing target unless you have specific reason to investigate it.
How many domains use DynDNS Mailhop?
192 domains in the Tranco top-1M use DynDNS Mailhop as their email service provider (ESP) as of September 20, 2026 (0.03% of SPF-publishing domains), according to Live Direct Marketing's daily DNS scan.
Is DynDNS Mailhop common enough to affect email deliverability testing?
DynDNS Mailhop accounts for 0.03% 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 DynDNS Mailhop most?
DynDNS Mailhop's largest TLD is .com (49.5% of its domains); it appears across 41 TLDs in total.