Tools
Blacklist check
Check whether an IPv4 address or a domain appears on the anti-spam lists (DNSBL) that email servers consult before accepting a message.
What a listing means
Email servers consult these lists to reject or mark as spam messages coming from suspicious addresses.
Why an IP ends up on a list
Usually because of a compromised email account, a contact form used for spam or an infected script.
What to check first
The server's mail queue, accounts with weak passwords and website forms, before requesting removal from the list.
Removal from the list
Most lists have a delisting form; some remove the address automatically after a few days without spam.
Domain lists
Domain lists (e.g. URIBL, SURBL) concern the links in messages, not the sending server.
Email delivery
Besides lists, SPF, DKIM and DMARC matter; you can see them with the WHOIS lookup, under the TXT records.
“No response” results
Some lists refuse queries that come through public DNS servers or above a certain limit; in that case the result is unknown, not “clean”.
Frequently asked questions
It is a public list of IP addresses or domains that have sent spam or shown suspicious activity. Email servers query it and may reject messages coming from listed addresses.
Find the cause (compromised account, abused form, infected script), fix it and then request delisting on the list's website. If you request delisting without fixing the cause, the address ends up on the list again.
Some lists (for example Spamhaus or URIBL) do not respond to queries coming through public DNS servers or above a free limit. In that case we do not know whether the address is listed, so we mark it neither clean nor listed.
No. The tool checks IPv4 addresses and domains; most lists used for email are still based on IPv4.
It can help, because the reputation of a dedicated IP depends only on your own messages. On some plans a dedicated IPv4 is included, on others you can add it for a fee. See the plan description.
