Zix SMB Hosted email service provider (ESP)
According to Live Direct Marketing's daily Tranco top-1M scan (September 18, 2026), Zix SMB Hosted is the email service provider (ESP) for 102 domains — 0.02% of 637,944 SPF-publishing domains. Detection method: include: mechanisms in the SPF record.
Key facts
- 102 domains in the Tranco top-1M use Zix SMB Hosted (0.02% of SPF-publishing domains).
- Snapshot date: 2026-09-18 — recomputed every day.
- Strongest TLD: .com (67.6% of its domains).
- Most co-used service: Microsoft 365.
- Directory category: email security gateway.
Why Zix SMB Hosted appears in this category
Zix (OpenText) — SMB email encryption + security.
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.
Zix SMB Hosted is an email hosting and management service operated by Zix Corporation, now part of the OpenText portfolio. It provides hosted email infrastructure, DNS and authentication management, and supplementary email services such as encryption and archival for small-to-medium businesses.
Zix's operational footprint is concentrated in the long tail of smaller organisations within the .com namespace, and it frequently appears alongside Microsoft 365 in sender authentication records. For email professionals, this means that Zix SPF includes are commonly encountered during deliverability audits and infrastructure reviews, particularly when investigating how smaller organisations handle multi-service email deployments.
Where Zix SMB Hosted 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 | 4 | 3.9% |
| Top 1,000,000 | 96 | 94.1% |
| Unranked | 2 | 2.0% |
Top-level domain split
| TLD | Domains | Share | |
|---|---|---|---|
| .com | 69 | 67.6% | |
| .org | 16 | 15.7% | |
| .gov | 6 | 5.9% | |
| .edu | 3 | 2.9% | |
| .bank | 2 | 2.0% | |
| .net | 2 | 2.0% | |
| .cl | 1 | 1.0% | |
| .xyz | 1 | 1.0% | |
| .ca | 1 | 1.0% | |
| .us | 1 | 1.0% |
What Zix SMB Hosted users also use
Cross-tabulated from the same daily snapshot — the other email services seen on the same 102 domains.
| Type | Service | Domains | Share of Zix SMB Hosted users |
|---|---|---|---|
| Mailbox | Microsoft 365 | 32 | 31.4% |
| Mailbox | Google Workspace | 18 | 17.6% |
| Mailbox | Unknown / Other | 18 | 17.6% |
| Mailbox | Mimecast | 12 | 11.8% |
| Mailbox | Proofpoint | 8 | 7.8% |
| Mailbox | Barracuda | 7 | 6.9% |
| ESP | SendGrid (Twilio) | 14 | 13.7% |
| ESP | Salesforce | 14 | 13.7% |
| ESP | Amazon SES | 11 | 10.8% |
| ESP | Mailgun | 11 | 10.8% |
Zix SMB Hosted in multi-service email architectures
When Zix SMB Hosted is deployed alongside Microsoft 365, both services require separate SPF includes in the organisation's authentication records. This co-deployment is common when Microsoft 365 handles primary email delivery whilst Zix manages supplementary services such as encryption or message archival. For deliverability teams, this multi-service setup requires careful DNS validation and coordination: authentication policies from both providers must not conflict, and mail-routing configurations from each service must be understood when troubleshooting delivery issues.
See the full Zix SMB Hosted data page (KPI cards, trend, sample domains) →
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Frequently asked questions
What should I know about Zix SMB Hosted for email deliverability?
Zix SMB Hosted is an email hosting and management service commonly used by smaller organisations, often deployed alongside Microsoft 365. When you encounter Zix SPF includes during email audits, it indicates the organisation is using Zix for services such as email encryption or message archival, which can affect how mail is authenticated and routed.
How many domains use Zix SMB Hosted?
102 domains in the Tranco top-1M use Zix SMB Hosted as their email service provider (ESP) as of September 18, 2026 (0.02% of SPF-publishing domains), according to Live Direct Marketing's daily DNS scan.
Is Zix SMB Hosted common enough to affect email deliverability testing?
Zix SMB Hosted 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 Zix SMB Hosted most?
Zix SMB Hosted's largest TLD is .com (67.6% of its domains); it appears across 10 TLDs in total.