Is my mail server on a blocklist?
Paste a mail domain to look up its MX hosts' addresses on Spamhaus ZEN, SpamCop, PSBL, UCEPROTECT, the 4 public blocklists (also called blacklists) receivers consult most. It runs once with a 10 second cap, the same runner a monitor uses; the result says where it ran.
How to read this
- Blocklists
- Up to 8 sending addresses, the MX hosts' IPv4 addresses, each checked against Spamhaus ZEN, SpamCop, PSBL, UCEPROTECT. A listing names the address and the list; a list that did not answer is marked not checkable, never clean.
- MX, SPF, DKIM and DMARC
- The records are read on the same run, so the plate shows the whole setup. The other pages read one area each.
Questions
Which lists does it check?
Spamhaus ZEN, SpamCop, PSBL, UCEPROTECT. Each zone answers with its own documented return codes; any other answer, including the ones a zone uses to refuse a query, is reported as not checkable rather than as a listing.
Can I check a single IP address?
Not here: the check starts from the domain and looks up the addresses its MX hosts resolve to, which is what a receiver sees on the connection. A monitor does the same every day and alerts on a new listing.
Related
Read
How to check a mail server against blocklists (and why "not checkable" is not "clear")What a DNS blocklist is, the four lists that get mail refused, how a listing happens, the dig command to check one, delisting, and why silence is not a pass.SPF, DKIM and DMARC explained: how to read the records and the mistakes that get mail rejectedWhat SPF, DKIM and DMARC each do, how to read a record term by term, the dig commands, and the mistakes that get legitimate mail rejected.
Watch this for good.
Start free