Act-On Software email service provider (ESP)
According to Live Direct Marketing's daily Tranco top-1M scan (September 13, 2026), Act-On Software is the email service provider (ESP) for 439 domains — 0.07% of 628,913 SPF-publishing domains. Detection method: include: mechanisms in the SPF record.
Key facts
- 439 domains in the Tranco top-1M use Act-On Software (0.07% of SPF-publishing domains).
- Snapshot date: 2026-09-13 — recomputed every day.
- Strongest TLD: .com (74.3% of its domains).
- Most co-used service: Microsoft 365.
- Directory category: email service provider.
Why Act-On Software appears in this category
Act-On — mid-market marketing automation platform.
We classify it as a email service provider 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.
Act-On Software is a marketing automation platform and email service provider that enables organisations to manage and send email campaigns, conduct lead nurturing, and automate marketing workflows. It delivers these messages through its own hosted infrastructure, which organisations authorise via email authentication mechanisms like SPF.
Act-On's footprint in email infrastructure is concentrated among smaller and mid-market organisations rather than enterprise brands, predominantly in the .com domain space. It frequently appears in email authentication records alongside Microsoft 365, reflecting adoption by organisations that integrate marketing automation with Microsoft's productivity platform.
Where Act-On Software sits in the Tranco ranking
| Tranco rank band | Domains | Share of its base |
|---|---|---|
| Top 1,000 | 1 | 0.2% |
| Top 10,000 | 2 | 0.5% |
| Top 100,000 | 52 | 11.8% |
| Top 1,000,000 | 382 | 87.0% |
| Unranked | 2 | 0.5% |
Top-level domain split
| TLD | Domains | Share | |
|---|---|---|---|
| .com | 326 | 74.3% | |
| .org | 64 | 14.6% | |
| .net | 10 | 2.3% | |
| .edu | 6 | 1.4% | |
| .ca | 5 | 1.1% | |
| .co.uk | 4 | 0.9% | |
| .co.nz | 3 | 0.7% | |
| .io | 2 | 0.5% | |
| .de | 2 | 0.5% | |
| .travel | 2 | 0.5% |
What Act-On Software users also use
Cross-tabulated from the same daily snapshot — the other email services seen on the same 439 domains.
| Type | Service | Domains | Share of Act-On Software users |
|---|---|---|---|
| Mailbox | Microsoft 365 | 215 | 49.0% |
| Mailbox | Google Workspace | 57 | 13.0% |
| Mailbox | Mimecast | 52 | 11.8% |
| Mailbox | Proofpoint | 25 | 5.7% |
| Mailbox | Unknown / Other | 23 | 5.2% |
| Mailbox | Barracuda | 20 | 4.6% |
| ESP | Salesforce | 67 | 15.3% |
| ESP | Mimecast | 56 | 12.8% |
| ESP | SendGrid (Twilio) | 55 | 12.5% |
| ESP | Amazon SES | 47 | 10.7% |
SPF Authentication and Act-On's Sending Infrastructure
Act-On Software appears in domain SPF records as an authorised external sender, permitting Act-On's infrastructure to send email on behalf of customer domains—typically marketing campaigns and automated sequences. This means a domain's email reputation is partly dependent on Act-On's operational standing, and issues with Act-On's sending practices or infrastructure reputation can directly affect deliverability of mail sent through it.
See the full Act-On Software data page (KPI cards, trend, sample domains) →
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Frequently asked questions
What is Act-On Software in email infrastructure?
Act-On Software is a marketing automation and email service provider used by organisations to send campaigns and automated email sequences. Its infrastructure appears in SPF authentication records as an authorised sender on behalf of customer domains.
How many domains use Act-On Software?
439 domains in the Tranco top-1M use Act-On Software as their email service provider (ESP) as of September 13, 2026 (0.07% of SPF-publishing domains), according to Live Direct Marketing's daily DNS scan.
Is Act-On Software common enough to affect email deliverability testing?
Act-On Software accounts for 0.07% 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 Act-On Software most?
Act-On Software's largest TLD is .com (74.3% of its domains); it appears across 23 TLDs in total.