Hostkarma, run by Junk Email Filter, doesn't just blacklist. One lookup tells a mail server whether an IP is trusted, mixed, suspicious, or a spam source, so the color you got matters.
| Color | What It Means | What to Do |
|---|---|---|
| White | Trusted, sends only good mail. | Nothing to do. |
| Yellow | Mix of good mail and spam, like big webmail providers. | Nothing to do; mail servers skip blacklist checks. |
| Brown | Sending spam, but not enough to blacklist yet. | Find the source now, before it turns black. |
| Black | Sending spam. | Fix the cause; the listing expires about five days later. |
Hostkarma counts the spam and good mail each IP sends to its network of servers, and it runs fake mail servers that only spam bots ever contact. Hitting one of those traps can blacklist a hacked machine right away.
Blacklist entries expire about five days after the spam stops, so fixing the source is the main job. To check your IP or request removal sooner, use Junk Email Filter's removal page.
Generator Labs checks your IPs against Hostkarma and hundreds of other blacklists and alerts you by email, Slack, SMS, or webhook when a listing appears. Free for your first host.
About five days after the spam stops.
A mixed source, like a big webmail provider. It isn't a blacklisting.
For small businesses and non-profits, yes.