Check your site is not listed on any security blacklists

15-20 min Impact: medium Effort: low ✓ Manual completion

Security blacklists (like Google Safe Browsing or major spam/malware block lists) flag sites that have been compromised or are distributing malware — being listed, even by mistake, can trigger browser warnings for every visitor or get your emails blocked outright.

A blacklisting event can happen even to a legitimate site that was briefly compromised, and it is worth actively checking rather than only discovering it when a visitor reports seeing a warning.

The full picture

Security blacklist status directly affects whether various security tools, email systems, and even some browsers actively warn visitors away from or entirely block access to your site — being listed, even due to a past issue that's since been resolved, can continue causing genuine, ongoing harm to your traffic and reputation until the listing is specifically identified and addressed.

This verification requires genuinely checking your domain against the actual, major blacklist services that security tools and email systems commonly reference — a domain can end up on these lists through various means, including a genuine past compromise, false positive detection, or even association with a previous owner's activity if you acquired a domain with existing history.

The genuine consequence of blacklist listing extends beyond simple reputation damage — depending on which specific list your domain appears on, this can result in browsers actively displaying security warnings to visitors, email systems rejecting or heavily filtering your outgoing email, or various security tools flagging your site as a genuine threat, each representing real, direct harm to your legitimate business operations.

Where a genuine listing is identified, most blacklist services provide a defined process for requesting delisting once you've confirmed and addressed whatever issue triggered the original listing — this process typically requires demonstrating the underlying issue has genuinely been resolved, making this remediation both a technical and, in some cases, a documentation and communication task with the specific listing service.

How to do it

1

Check major blacklist services directly

Google Safe Browsing, and general blacklist aggregator tools that check dozens of lists at once.
2

If listed, identify and fix the actual root cause first

Blacklisting almost always means something genuinely was compromised or misconfigured — fix that before requesting removal.
3

Request delisting through the proper process

Each blacklist has its own request process, typically through Google Search Console for Safe Browsing specifically.
4

Re-check periodically

A quick recurring check catches a future listing early rather than after visitors start reporting warnings.

Common mistakes

Requesting delisting before actually fixing the underlying compromise typically results in being re-listed shortly after — always confirm the root cause is resolved first.