Blocklist check for email and sign-up problems
Find out whether an IPv4 address appears on the DNS blocklists (DNSBLs) that mail servers and anti-abuse services consult. Your own address is filled in already. To check another one, such as a proxy exit IP or the office mail server, type it over.
| Blocklist | Zone | Status |
|---|---|---|
| Spamhaus ZEN | zen.spamhaus.org | Clean |
| Barracuda | b.barracudacentral.org | Clean |
| SpamCop | bl.spamcop.net | Clean |
| SORBS | dnsbl.sorbs.net | Clean |
| UCEPROTECT L1 | dnsbl-1.uceprotect.net | Clean |
| PSBL | psbl.surriel.com | Clean |
| WPBL | db.wpbl.info | Clean |
| s5h.net | all.s5h.net | Clean |
Read these results as a first check. Some blocklists won’t answer lookups made through large public resolvers, which means a Clean result here may be mistaken. Before acting on a listing or a clean result, confirm it on the blocklist’s own website.
What a listing means for your business
A DNS-based blocklist (DNSBL) names IP addresses linked to spam or other abuse. Receiving mail servers look up the sending IP as each message arrives, then deliver it, divert it to spam or reject it; some websites use the same lists as one factor among several. For a business, a listing usually shows up first as newsletters, invoices or order confirmations that land in spam folders or bounce.
Reputation and the proxies your team uses
Every IP brings its history with it. Addresses from free or shared proxies are the most likely to carry abuse records from earlier users, which can mean refused sign-ups and more blocks during legitimate work. Our residential premium pool, the source of our static ISP addresses too, is monitored to keep its reputation high, and dedicated options mean an address isn’t shared with other customers. To see what you’ve been given, test the proxy in our proxy checker, open the IP checker through it, then run the exit IP through this page.
Getting an address removed from a list
If the listed address belongs to your company, for example the office mail server, start with the source: track down the device or account that sent the spam and secure it. Then search for the IP on that blocklist’s website and submit a removal request there. Many listings also lapse by themselves once the abuse stops. Proxy addresses are a different case: the provider controls them, so report the listing to their support team.
Questions teams ask about blocklists
What does it mean if one of our IPs is on a blocklist?
A blocklist operator has recorded spam or abuse from that address. Mail servers, and some websites, check these DNS-based lists before accepting traffic, so a listed IP can see emails rejected or filtered and some sign-ups refused.
How did our address end up listed?
Often through no fault of your own. A previous user of the IP may have sent spam, a compromised laptop or account on your network may be sending it now, or the address may share a server with abusive neighbours. Listings usually lapse when the abuse ends, and most lists publish a removal process.
Should we stop using a proxy IP that shows up as listed?
Not necessarily. These lists are built mainly around email abuse, so a listed proxy IP often works normally for browsing, price checks and ad reviews. Our dedicated and premium pools are monitored to keep their reputation high.
Who can get an address removed from a list?
Removal is up to the operator of each blocklist. Deal with whatever caused the listing, then find the IP on that list's website and submit a removal request there.
