ISP email domains: Comcast, AT&T, BT and other internet providers
ISP addresses come with a home internet plan. They belong to individuals, so treat them like personal email, not like a company.
Internet providers have handed out mailboxes for decades: comcast.net, att.net, verizon.net, btinternet.com, orange.fr. Lots of people still use them as their main address.
The trap is enrichment. Without an ISP category, comcast.net looks like a company domain, and a lead from it gets enriched as "Comcast, 180,000 employees". That is how a retiree ends up in your enterprise pipeline.
pingutil keeps a list of about 60 consumer ISP mail domains and returns "isp" for them, so you can treat those addresses as personal.
How pingutil detects it
A per-domain lookup in the ISP list. Checked after the disposable and free-webmail lists, before falling through to "company".
POST /v1/lookup
{ "input": "someone@comcast.net" }
→ { "category": "isp", ... }Example domains
A few well-known ones. The list covers about 60 domains.
- comcast.net
- att.net
- verizon.net
- sbcglobal.net
- cox.net
- charter.net
- bellsouth.net
- btinternet.com
- orange.fr
Common questions
- Why not just call ISP mail "free"?
- Both are personal, but some teams want to tell them apart. ISP mail often signals a less technical, older audience and is tied to a home internet contract.
- Is comcast.com treated the same as comcast.net?
- No. comcast.com is the company's corporate domain; comcast.net is the consumer mail domain. Only the consumer mail domains are on the ISP list.
Related guides
- ISP email domains: why comcast.net is not a company
comcast.net, btinternet.com and orange.fr are consumer ISP mailboxes. Why they break lead enrichment and routing, which domains to list, and how to treat them.
- How to tell a business email from a personal one in code
Classify an email as business or personal: reduce to the registrable domain, check provider lists, then use MX records to catch personal custom domains.
- CRM data hygiene: cleaning contacts by email domain
Clean up a CRM by email domain: normalize company domains, merge duplicate accounts, separate personal and disposable contacts, and keep it clean.
Check a domain now
Run any address through the live demo, or get an API key for your app.