Windstream is an US regional ISP mailbox. Across 56,582 Windstream addresses verified by BounceZero between April and October 2026, 49.6% were invalid, 0.0% catch-all, 0.1% unknown and 50.2% confirmed valid. The invalid share is far above the business average.
The Windstream row is all 56,582 addresses verified in the six months to October 2026; the other rows are the benchmarks from the same corpus. Risky and role results fill each row to 100%.
| Segment | Addresses | Invalid | Catch-all | Unknown | Confirmed valid |
|---|---|---|---|---|---|
| Windstream | 56,582 | 49.6% | 0.0% | 0.1% | 50.2% |
| All non-freemail domains (business and ISP) | 6,514,884 | 14.5% | 2.3% | 27.0% | 32.6% |
| Business domains only (consumer ISP and freemail excluded) | 1,269,919 | 22.9% | 9.4% | 22.5% | 40.3% |
| All freemail | 1,415,154 | 17.6% | 1.1% | 2.1% | 74.0% |
| All .net addresses | 1,252,193 | 17.6% | 0.6% | 28.8% | 19.9% |
Non-freemail includes consumer ISP mailboxes; a business-only cut is on the benchmarks page. Method and every other cut: Lead List Quality Benchmarks 2026. Risky and role on the Windstream row: 0.0%.
Windstream answers probes decisively and half of its addresses verify as invalid, with the other half confirmed valid. Regional US ISPs lose mailboxes as customers switch to cable and fibre, and the dormant accounts are closed rather than parked.
Windstream is a regional US telecom serving rural areas in the South and Midwest, and its mailboxes belong to customers who stayed on its broadband service. The gateway answers decisively, so the invalid half of the segment is reliably dead and the valid half reliably reachable. The surviving contacts are often small-town businesses, farms and trades, which can be a useful segment for regional campaigns under CAN-SPAM with an opt-out.
On confirmed-invalid rate, Windstream ranks 4 of 29 providers in the corpus, just behind iCloud Mail at 73.0%, ahead of Telefónica at 42.8%.
On unknown rate, Windstream ranks 26 of 29 providers in the corpus, just behind Live.nl at 0.7%, ahead of Hotmail at 0.0%.
On confirmed-valid share, Windstream ranks 8 of 29 providers in the corpus, just behind Hotmail Netherlands at 50.3%, ahead of Telefónica at 48.5%.
How to read these rates: they are BounceZero's probe outcomes on customer lists over April to October 2026, not a census of Windstream mailboxes. Unknown and catch-all measure what verification could not confirm, which depends on the provider's gateway policy during the window as much as on the addresses. The lists are the ones customers chose to upload, so segments dominated by a few large uploads carry their age and source. Method and limitations: benchmarks page.
Windstream rarely returns unknown. When it does, re-check once; a second unknown usually means a dormant mailbox.
Windstream fails at 49.6%, which is 3.4 times the business-list rate; the segment is a relic and so, probably, is the list around it.
Catch-all is negligible on Windstream (0.0%); when this provider does return valid, the mailbox accepted the probe itself rather than a blanket accept.
Just over 50% confirmed valid: reachable today, re-verified before every send, since only 19.2% of addresses were still valid 90 days after a check in BounceZero's decay study.
Reliable verdicts: act on them. The invalid half is gone for good; the valid half is reachable and tends to be small-business owners in the ISP's footprint.
Role addresses such as info@ and sales@ make up 0.0% of Windstream addresses in the corpus. Role addresses are rare here, as expected for a mailbox provider.
49.6% of 56,582 Windstream addresses verified by BounceZero between April and October 2026 were confirmed invalid, against 14.5% across non-freemail domains and 17.6% across freemail.
0.1%. Unknown means the mailbox could not be confirmed either way, usually because the gateway deferred the probe. BounceZero refunds unknown results; on Windstream it is rare enough to re-check once and move on.
Not in practice: 0.0% of Windstream addresses returned catch-all, so a valid verdict means the mailbox exists.
50.2% confirmed valid at verification time. Keep bounces under 2% and complaints under 0.3% on the send, and re-verify the segment before every send.
Upload the file and see valid, invalid, catch-all and unknown per row, with the Windstream segment against this benchmark. 100 free checks a month, unknowns refunded.
Ayoub built BounceZero's 5-stage validation pipeline, its dedicated BGP-announced IP infrastructure, and the Patroni HA PostgreSQL cluster behind every verification. Previously built high-volume email delivery infrastructure. Trained at 1337 Benguerir (École 42 network, 2019). Open-source: bgp_analyzer.
Invalid, catch-all and unknown rates per email provider and country domain, 2026
21,194 .uk addresses verified April to October 2026
10,998 .us addresses verified April to October 2026
36,082 Xtra (Spark) addresses verified April to October 2026
21,081 Yahoo Mail addresses verified April to October 2026
16,114 .ae addresses verified April to October 2026
1,178,297 Alice (TIM) addresses verified April to October 2026
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