According to Live Direct Marketing's daily Tranco top-1M scan (July 12, 2026), AppRiver (Zix) is the email service provider (ESP) for 119 domains — 0.02% of 617,244 SPF-publishing domains. Detection method: include: mechanisms in the SPF record.
AppRiver, now part of Zix Corporation, is an email service provider offering transmission and security services to organisations of various sizes. Its IP ranges appear in SPF records across millions of websites, making it part of the mail infrastructure that both senders and receiving systems must account for.
AppRiver's deployment pattern concentrates in smaller organisations and the .com space rather than the largest brands. Its SPF includes frequently co-occur with unclear or unidentified sender configurations, suggesting that AppRiver adoption correlates with simpler, less-documented mail setups—a pattern affecting how reputation systems and receiving organisations evaluate the email streams they handle.
| Tranco rank band | Domains | Share of its base |
|---|---|---|
| Top 1,000 | 0 | 0.0% |
| Top 10,000 | 0 | 0.0% |
| Top 100,000 | 10 | 8.4% |
| Top 1,000,000 | 88 | 73.9% |
| Unranked | 21 | 17.6% |
| TLD | Domains | Share | |
|---|---|---|---|
| .com | 85 | 71.4% | |
| .org | 16 | 13.4% | |
| .net | 6 | 5.0% | |
| .co.uk | 5 | 4.2% | |
| .ca | 2 | 1.7% | |
| .ch | 2 | 1.7% | |
| .edu | 2 | 1.7% | |
| .de | 1 | 0.8% |
Cross-tabulated from the same daily snapshot — the other email services seen on the same 119 domains.
| Type | Service | Domains | Share of AppRiver (Zix) users |
|---|---|---|---|
| Mailbox | Unknown / Other | 70 | 58.8% |
| Mailbox | Microsoft 365 | 26 | 21.8% |
| Mailbox | Google Workspace | 7 | 5.9% |
| Mailbox | Proofpoint Essentials | 3 | 2.5% |
| Mailbox | Proofpoint | 3 | 2.5% |
| Mailbox | Mimecast | 3 | 2.5% |
| ESP | HubSpot | 17 | 14.3% |
| ESP | SendGrid (Twilio) | 16 | 13.4% |
| ESP | Amazon SES | 16 | 13.4% |
| ESP | Mandrill | 13 | 10.9% |
AppRiver infrastructure appears predominantly in SPF records of smaller organisations and frequently alongside unclear sender configurations. Where AppRiver and limited sender documentation coincide, receiving systems may lack the context to evaluate mail streams confidently; organisations relying on AppRiver should prioritise clear authentication practices (DKIM, DMARC) and sender identity documentation to reduce ambiguity in how the mail stack is perceived.
See the full AppRiver (Zix) data page (KPI cards, trend, sample domains) →
AppRiver serves smaller and mid-market organisations; when these add its IP ranges to their SPF records, it becomes visible in broad internet scans. Its concentration in the long tail reflects its customer demographic rather than any technical limitation.
119 domains in the Tranco top-1M use AppRiver (Zix) as their email service provider (ESP) as of July 12, 2026 (0.02% of SPF-publishing domains), according to Live Direct Marketing's daily DNS scan.
AppRiver (Zix) 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.
AppRiver (Zix)'s largest TLD is .com (71.4% of its domains); it appears across 8 TLDs in total.