According to Live Direct Marketing's daily Tranco top-1M scan (July 13, 2026), Mailchimp is the email service provider (ESP) for 22,789 domains — 3.69% of 617,702 SPF-publishing domains. Detection method: include: mechanisms in the SPF record.
Mailchimp is an email service provider (ESP) operated by Intuit, offering email marketing, automation, and campaign management tools to senders of all sizes. The service handles the dispatch, tracking, and management of email campaigns through Mailchimp's shared infrastructure and signing systems.
Mailchimp's presence in email traffic is concentrated among smaller and mid-market organisations, particularly within the .com domain space, and often appears alongside Google Workspace deployments. For email professionals, this means Mailchimp's SPF includes and sender reputation signals are regularly encountered when auditing authentication chains—especially for small publishers, nonprofits, and support organisations using integrated email platforms.
| Tranco rank band | Domains | Share of its base |
|---|---|---|
| Top 1,000 | 33 | 0.1% |
| Top 10,000 | 324 | 1.4% |
| Top 100,000 | 2,966 | 13.0% |
| Top 1,000,000 | 17,545 | 77.0% |
| Unranked | 1,921 | 8.4% |
| TLD | Domains | Share | |
|---|---|---|---|
| .com | 11,600 | 50.9% | |
| .org | 2,014 | 8.8% | |
| .nl | 609 | 2.7% | |
| .co.uk | 589 | 2.6% | |
| .net | 463 | 2.0% | |
| .de | 435 | 1.9% | |
| .com.au | 415 | 1.8% | |
| .io | 325 | 1.4% | |
| .ca | 299 | 1.3% | |
| .cz | 289 | 1.3% |
Cross-tabulated from the same daily snapshot — the other email services seen on the same 22,789 domains.
| Type | Service | Domains | Share of Mailchimp users |
|---|---|---|---|
| Mailbox | Google Workspace | 9,088 | 39.9% |
| Mailbox | Microsoft 365 | 7,276 | 31.9% |
| Mailbox | Self-Hosted | 1,380 | 6.1% |
| Mailbox | Unknown / Other | 1,073 | 4.7% |
| Mailbox | Mimecast | 689 | 3.0% |
| Mailbox | Proofpoint | 432 | 1.9% |
| ESP | Mandrill | 4,471 | 19.6% |
| ESP | Amazon SES | 3,264 | 14.3% |
| ESP | SendGrid (Twilio) | 3,064 | 13.4% |
| ESP | Zendesk | 2,987 | 13.1% |
Mailchimp publishes SPF include mechanisms (such as include:mailchimp.com) that authorise the service to send email on a customer's behalf. Because Mailchimp is a multi-tenant platform, the reputation of that include is distributed across thousands of customers; sending practices of any one Mailchimp sender affect authentication outcomes and inbox placement for all others sharing the same include. This means smaller organisations benefit from Mailchimp's institutional sending volume and infrastructure stability, but also inherit the shared-reputation risk that comes with multi-tenant signing—a practical reason why larger senders often transition to dedicated IP pools or self-hosted authentication mechanisms.
See the full Mailchimp data page (KPI cards, trend, sample domains) →
Testing against Mailchimp is worthwhile if your recipients or partners send campaigns through the platform, as understanding Mailchimp's SPF, DKIM, and DMARC behaviour informs alignment audits. If your organisation uses a different ESP or sends from your own infrastructure, direct testing against Mailchimp is less critical than verifying your own sender reputation and authentication setup.
22,789 domains in the Tranco top-1M use Mailchimp as their email service provider (ESP) as of July 13, 2026 (3.69% of SPF-publishing domains), according to Live Direct Marketing's daily DNS scan.
Mailchimp accounts for 3.69% 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.
Mailchimp is growing — its share moved +0.03 pp over the last 30 days (as of July 13, 2026).
Mailchimp's largest TLD is .com (50.9% of its domains); it appears across 321 TLDs in total.