According to Live Direct Marketing's daily Tranco top-1M scan (July 13, 2026), Campaign Monitor is the email service provider (ESP) for 3,465 domains — 0.56% of 617,702 SPF-publishing domains. Detection method: include: mechanisms in the SPF record.
Campaign Monitor is a cloud-based email service platform for sending, tracking, and managing email campaigns and transactional messages. It provides infrastructure for organisations to deliver marketing and customer communication email at scale.
Campaign Monitor's deployment is concentrated among smaller and mid-market organisations, particularly those within the .com domain space and users of Microsoft 365. This footprint matters for email infrastructure: recipients filtering mail from Campaign Monitor senders must distinguish legitimate campaign mail from spoofed variants, which requires proper SPF, DKIM, and DMARC authentication on the sender side. For senders using Campaign Monitor, shared infrastructure means individual sender reputation is intertwined with the platform's wider IP pool reputation—a critical consideration for inbox placement.
| Tranco rank band | Domains | Share of its base |
|---|---|---|
| Top 1,000 | 4 | 0.1% |
| Top 10,000 | 35 | 1.0% |
| Top 100,000 | 455 | 13.1% |
| Top 1,000,000 | 2,638 | 76.1% |
| Unranked | 333 | 9.6% |
| TLD | Domains | Share | |
|---|---|---|---|
| .com | 1,674 | 48.3% | |
| .org | 325 | 9.4% | |
| .com.au | 208 | 6.0% | |
| .co.uk | 189 | 5.5% | |
| .au | 110 | 3.2% | |
| .be | 80 | 2.3% | |
| .net | 61 | 1.8% | |
| .nl | 59 | 1.7% | |
| .ca | 58 | 1.7% | |
| .de | 48 | 1.4% |
Cross-tabulated from the same daily snapshot — the other email services seen on the same 3,465 domains.
| Type | Service | Domains | Share of Campaign Monitor users |
|---|---|---|---|
| Mailbox | Microsoft 365 | 1,334 | 38.5% |
| Mailbox | Google Workspace | 949 | 27.4% |
| Mailbox | Mimecast | 238 | 6.9% |
| Mailbox | Unknown / Other | 183 | 5.3% |
| Mailbox | Self-Hosted | 142 | 4.1% |
| Mailbox | Proofpoint | 111 | 3.2% |
| ESP | Amazon SES | 490 | 14.1% |
| ESP | SendGrid (Twilio) | 433 | 12.5% |
| ESP | Zendesk | 328 | 9.5% |
| ESP | Salesforce | 325 | 9.4% |
Campaign Monitor distributes email from many customers across a shared set of sending IP addresses and domains, pooling them under mechanisms like SPF includes. This means a single customer's poor list hygiene, weak authentication, or compromised credentials can degrade inbox placement for unrelated senders also using the platform. Email recipients' filters account for this by evaluating the entire Campaign Monitor IP pool's reputation in parallel with individual sender DKIM signatures and DMARC alignment; senders relying on Campaign Monitor must therefore maintain strict bounce handling, monitor complaint rates, and implement list segmentation to preserve their share of the platform's collective reputation.
See the full Campaign Monitor data page (KPI cards, trend, sample domains) →
A Campaign Monitor reference in an email header indicates the sender used Campaign Monitor's platform to deliver that message. It is a legitimate email service provider; the presence of Campaign Monitor identifies the delivery infrastructure, not the legitimacy of the mail itself—that depends on whether you subscribed to email from the sender.
3,465 domains in the Tranco top-1M use Campaign Monitor as their email service provider (ESP) as of July 13, 2026 (0.56% of SPF-publishing domains), according to Live Direct Marketing's daily DNS scan.
Campaign Monitor accounts for 0.56% 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.
Campaign Monitor is growing — its share moved +0.01 pp over the last 30 days (as of July 13, 2026).
Campaign Monitor's largest TLD is .com (48.3% of its domains); it appears across 129 TLDs in total.