According to Live Direct Marketing's daily Tranco top-1M scan (July 12, 2026), Reply.io is the email service provider (ESP) for 95 domains — 0.02% of 617,244 SPF-publishing domains. Detection method: include: mechanisms in the SPF record.
Reply.io is a sales engagement platform that provides email services for outbound prospecting campaigns. It operates as an email service provider for teams running coordinated outreach workflows, commonly integrated with Google Workspace.
Reply.io's footprint is concentrated in smaller businesses and independent teams using .com domains, rather than Fortune 500 deployments. For anyone sending or receiving email, this means Reply.io represents a significant portion of automated business outreach, and its proper configuration—SPF records, DKIM signing, DMARC policy—affects how mail systems classify and route this traffic.
| Tranco rank band | Domains | Share of its base |
|---|---|---|
| Top 1,000 | 0 | 0.0% |
| Top 10,000 | 1 | 1.1% |
| Top 100,000 | 16 | 16.8% |
| Top 1,000,000 | 72 | 75.8% |
| Unranked | 6 | 6.3% |
| TLD | Domains | Share | |
|---|---|---|---|
| .com | 76 | 80.0% | |
| .co | 7 | 7.4% | |
| .io | 3 | 3.2% | |
| .net | 2 | 2.1% | |
| .group | 1 | 1.1% | |
| .eu | 1 | 1.1% | |
| .org | 1 | 1.1% | |
| .tech | 1 | 1.1% | |
| .cc | 1 | 1.1% | |
| .build | 1 | 1.1% |
Cross-tabulated from the same daily snapshot — the other email services seen on the same 95 domains.
| Type | Service | Domains | Share of Reply.io users |
|---|---|---|---|
| Mailbox | Google Workspace | 80 | 84.2% |
| Mailbox | Microsoft 365 | 6 | 6.3% |
| Mailbox | Mimecast | 3 | 3.2% |
| Mailbox | Trend Micro | 1 | 1.1% |
| Mailbox | Zoho Mail (EU) | 1 | 1.1% |
| Mailbox | Cisco IronPort | 1 | 1.1% |
| ESP | HubSpot | 33 | 34.7% |
| ESP | Zendesk | 19 | 20.0% |
| ESP | Mailchimp | 19 | 20.0% |
| ESP | Amazon SES | 18 | 18.9% |
Reply.io deployments frequently relay outbound mail through Google Workspace's SMTP services, meaning sender reputation is established jointly by the Google Workspace account and Reply.io's infrastructure. This arrangement centralises authentication—the sending domain's SPF record typically includes Google's SPF token—but distributes reputation risk: high-volume prospecting from a shared Google Workspace account can affect both the individual domain and Google Workspace's broader sending reputation. Administrators and senders should monitor bounce rates and feedback loops closely when using Reply.io over Google Workspace SMTP.
See the full Reply.io data page (KPI cards, trend, sample domains) →
Reply.io itself is not a spam service—it is a legitimate sales platform—but individual campaigns can be misconfigured or abused. Rather than blanket whitelisting, mail administrators should evaluate Reply.io senders based on authentication compliance (SPF, DKIM, DMARC), list management practices, and complaint feedback loops.
95 domains in the Tranco top-1M use Reply.io 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.
Reply.io 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.
Reply.io's largest TLD is .com (80.0% of its domains); it appears across 11 TLDs in total.