HDEMS email service provider (ESP)
According to Live Direct Marketing's daily Tranco top-1M scan (September 12, 2026), HDEMS is the email service provider (ESP) for 497 domains — 0.08% of 629,828 SPF-publishing domains. Detection method: include: mechanisms in the SPF record.
Key facts
- 497 domains in the Tranco top-1M use HDEMS (0.08% of SPF-publishing domains).
- Snapshot date: 2026-09-12 — recomputed every day.
- Strongest TLD: .co.jp (59.8% of its domains).
- Most co-used service: Microsoft 365.
- Directory category: email service provider.
Why HDEMS appears in this category
HDEMS — outsourced email marketing operations.
We classify it as a email service provider 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.
HDEMS is a Japanese email service provider that processes mail for a subset of web properties, primarily in the Japanese market. It is detected in email infrastructure through SPF include records, where it appears alongside other mail processors in authentication configurations.
Because HDEMS concentrates in smaller sites rather than global enterprise scale, and clusters heavily within .co.jp domains, its presence typically signals regional or SMB-focused mail infrastructure. Its frequent pairing with Microsoft 365 in SPF records suggests some organisations use HDEMS alongside or in transition from Microsoft's platform, which is relevant for understanding the delivery behaviour of such hybrid setups.
Where HDEMS sits in the Tranco ranking
| Tranco rank band | Domains | Share of its base |
|---|---|---|
| Top 1,000 | 1 | 0.2% |
| Top 10,000 | 6 | 1.2% |
| Top 100,000 | 50 | 10.1% |
| Top 1,000,000 | 439 | 88.3% |
| Unranked | 1 | 0.2% |
Top-level domain split
| TLD | Domains | Share | |
|---|---|---|---|
| .co.jp | 297 | 59.8% | |
| .com | 82 | 16.5% | |
| .jp | 70 | 14.1% | |
| .or.jp | 19 | 3.8% | |
| .ac.jp | 12 | 2.4% | |
| .net | 4 | 0.8% | |
| .coop | 3 | 0.6% | |
| .ne.jp | 2 | 0.4% | |
| .org | 2 | 0.4% | |
| .co.th | 1 | 0.2% |
What HDEMS users also use
Cross-tabulated from the same daily snapshot — the other email services seen on the same 497 domains.
| Type | Service | Domains | Share of HDEMS users |
|---|---|---|---|
| Mailbox | Microsoft 365 | 251 | 50.5% |
| Mailbox | Google Workspace | 162 | 32.6% |
| Mailbox | Trend Micro | 17 | 3.4% |
| Mailbox | SecureMX (JP) | 15 | 3.0% |
| Mailbox | Symantec MessageLabs | 14 | 2.8% |
| Mailbox | Proofpoint | 11 | 2.2% |
| ESP | Amazon SES | 87 | 17.5% |
| ESP | Salesforce | 73 | 14.7% |
| ESP | Repica WebCAS | 45 | 9.1% |
| ESP | CrmStyle | 32 | 6.4% |
SPF authentication layering and regional ISP reputation
HDEMS appears most often in SPF records as one component of multi-hop mail authentication chains, particularly alongside Microsoft 365, suggesting organisations using multiple processors rather than HDEMS alone. When your mail enters HDEMS as part of such a chain, that provider's IP reputation and its relationships with Japanese ISPs and mailbox providers can influence delivery, even if HDEMS is not your primary platform. Understanding HDEMS's regional reputation standing becomes relevant to your send quality if your infrastructure routes through it.
See the full HDEMS data page (KPI cards, trend, sample domains) →
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Frequently asked questions
What is HDEMS and should I test email delivery to it?
HDEMS is a regional Japanese email service provider; test against it only if your primary audience is in Japan or you operate a Japan-targeted service.
How many domains use HDEMS?
497 domains in the Tranco top-1M use HDEMS as their email service provider (ESP) as of September 12, 2026 (0.08% of SPF-publishing domains), according to Live Direct Marketing's daily DNS scan.
Is HDEMS common enough to affect email deliverability testing?
HDEMS accounts for 0.08% 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 HDEMS most?
HDEMS's largest TLD is .co.jp (59.8% of its domains); it appears across 15 TLDs in total.