Cisco IronPort (ICPbounce) email provider statistics and deliverability context
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According to Live Direct Marketing's daily Tranco top-1M scan (September 12, 2026), Cisco IronPort (ICPbounce) is the email service provider (ESP) for 288 domains — 0.05% of 629,828 SPF-publishing domains. Its strongest TLD is .com (62.8% of its domains). Detection: include: mechanisms in the SPF record.
Last updated from the 2026-09-12 DNS snapshot.
What Cisco IronPort (ICPbounce) represents in this dataset
Cisco IronPort — bounce-handling SPF domain.
Directory category: Gateway. The classification comes from include: mechanisms in the SPF record. It describes observed DNS infrastructure, not a commercial relationship and not the placement of any individual message.
What the 2026-09-12 snapshot shows about Cisco IronPort (ICPbounce)
Across 27 distinct TLDs its top three are .com (62.8%), .org (17.7%), .net (3.5%) — together 84.0% of the 288 domains, which makes the footprint narrow — three TLDs cover most of it, which is typical of a regional or single-market operator. The service most often observed on the same domains is Microsoft 365 (Mailbox, 104 domains, 36.1% of them), followed by Google Workspace (25.7%). Directly comparable by the same detection rule: Amazon SES, SendGrid (Twilio), Mailgun. Ranking between them reflects what is published in DNS, not delivery quality or volume sent. All figures come from a single daily DNS snapshot (2026-09-12); a domain appears here when its published records match the include: mechanisms in the SPF record rule, which is an infrastructure fact, not a commercial relationship.
Commonly used together with Cisco IronPort (ICPbounce)
What else the same 288 domains use — cross-tabulated from the same daily snapshot (2026-09-12).
| Type | Service | Domains | Share of Cisco IronPort (ICPbounce) users |
|---|---|---|---|
| Mailbox | Microsoft 365 | 104 | 36.1% |
| Mailbox | Google Workspace | 74 | 25.7% |
| Mailbox | Mimecast | 23 | 8.0% |
| Mailbox | Proofpoint | 20 | 6.9% |
| Mailbox | Unknown / Other | 14 | 4.9% |
| Mailbox | Self-Hosted | 11 | 3.8% |
| ESP | SendGrid (Twilio) | 37 | 12.8% |
| ESP | Amazon SES | 36 | 12.5% |
| ESP | HubSpot | 24 | 8.3% |
| ESP | Mimecast | 20 | 6.9% |
TLD distribution (top 27 of 27)
Frequently asked questions
How many domains use Cisco IronPort (ICPbounce)?
288 domains in the Tranco top-1M use Cisco IronPort (ICPbounce) as their email service provider (ESP) as of September 12, 2026, according to Live Direct Marketing's daily DNS scan.
What is Cisco IronPort (ICPbounce)'s market share?
Cisco IronPort (ICPbounce) holds 0.05% of SPF-publishing domains in the Tranco top-1M (snapshot of 2026-09-12). The number is recomputed every day.
What are the biggest alternatives to Cisco IronPort (ICPbounce)?
The largest email service provider (ESP)s in the same category by Tranco top-1M share are: Amazon SES, SendGrid (Twilio), Mailgun, Zendesk, Mailchimp (as of 2026-09-12).
Largest email service provider (ESP)s in this category
Amazon SES (6.18%) · SendGrid (Twilio) (4.63%) · Mailgun (4.01%) · Zendesk (3.76%) · Mailchimp (3.57%) · Mandrill (3.25%) · HubSpot (3.11%) · Salesforce (2.55%) · Mailjet (Sinch) (2.12%) · Cloudflare Email Routing (1.94%)
Domain sample (top 100 by Tranco rank)
Showing 100 of 288 domains.