Quad9 flagged my website — how removal works
CATALOG ENTRY VERIFIED 2026-10-09
Quad9 is a filtering DNS service: devices, routers and networks that use it ask it for a site's address, and for a domain on its blocklist it answers with nothing usable, so the site doesn't load for them. It accepts website false-positive reports by email request. unflagdomain sends that request for you as part of a €39 dispatch; Quad9 reviews the site itself and decides on its own schedule.
| List type | DNS filter |
|---|---|
| Channel | Email request |
| What unflagdomain does | Sends the request for you |
| Step-by-step guide | Not yet — the general process below applies |
| Longer read | Why Quad9 flags clean sites |
What Quad9 is
Quad9 is a free public DNS resolver (9.9.9.9) run by a Swiss non-profit. It refuses to resolve domains that its threat-intelligence providers list as malicious; its own result page shows the block and which providers listed the domain.
What a Quad9 flag looks like
The site doesn't load at all — the browser shows a 'site can't be reached' / DNS error — for people whose device, router or network uses Quad9.
Why clean sites end up flagged here
- A threat-intelligence provider whose feed the service uses listed the domain after seeing malware, phishing or spam on it.
- A single automated sighting, or shared infrastructure with something that was flagged, with no human review.
- A past compromise that has been cleaned, still listed until someone asks for a re-check.
How a removal request reaches Quad9
This vendor accepts a website false-positive report by email at an address it publishes in its own documentation. The message must be plain text, come from an address at the affected domain or a contact the vendor can verify, and state the URL, what was found, what was removed and when.
The general procedure — clean, verify from outside, one specific request, wait for the re-check — is in the complete removal guide, with the checklist of what every request must contain.
What unflagdomain does for this vendor
When a scan shows this vendor flagging your domain, a separately written plain-text request goes out to it in the dispatch, with your address as Reply-To, so the vendor's answer lands in your inbox. If the address bounces, another working contact is looked for and the request re-sent.
This is one of 135 vendors in the catalog. A scan shows which of them flag a domain right now; the €39 dispatch covers every one that does.
Quad9 is a filtering DNS service: devices, routers and networks that use it ask it for a site's address, and for a domain on its blocklist it answers with nothing usable, so the site doesn't load for them. A threat-intelligence provider whose feed the service uses listed the domain after seeing malware, phishing or spam on it. A single automated sighting, or shared infrastructure with something that was flagged, with no human review.
Clean the site first and verify it from outside. Then this vendor accepts a website false-positive report by email at an address it publishes in its own documentation. The message must be plain text, come from an address at the affected domain or a contact the vendor can verify, and state the URL, what was found, what was removed and when. State the URL, what was found, what was removed and when, in plain text.
Quad9 publishes no turnaround, and we don't promise one.
When a scan shows this vendor flagging your domain, a separately written plain-text request goes out to it in the dispatch, with your address as Reply-To, so the vendor's answer lands in your inbox. If the address bounces, another working contact is looked for and the request re-sent. We guarantee the request is sent or prepared; Quad9 decides the outcome.