IP Cleaning & Blacklist Removal for IPv4 Blocks
An IPv4 block with a bad history can lose much of its value: emails land in spam, services refuse connections and customers complain. BRENAC audits the reputation of your addresses […]
An IPv4 block with a bad history can lose much of its value: emails land in spam, services refuse connections and customers complain. BRENAC audits the reputation of your addresses and works to clear them, before you buy, lease or put them into production.
Why an IPv4 block's reputation matters
Every IPv4 address has a history. A block previously used for spam, scanning or abuse may be listed on one or more blacklists, and those listings follow the addresses to their new holder.
The consequences are concrete:
- Undelivered email: mail servers using blocklists reject or filter messages from listed addresses.
- Blocked services: firewalls, CDNs and security tools may refuse traffic from addresses with a poor reputation.
- Wrong location data: geolocation databases may still place the block in its previous country, which breaks regional content and licensing.
- Lower resale or lease value: a clean, documented block is easier to place and justifies a better price.
What we check
| Area | What we look at | Why it matters |
|---|---|---|
| Blacklists (DNSBL) | Listings on major spam and abuse blocklists, such as Spamhaus and Barracuda | Determines whether mail and traffic are rejected |
| Sender reputation | Reputation scores from email security vendors | Affects inbox placement even without a formal listing |
| Geolocation | Country and region recorded by commercial geolocation databases | Prevents access errors and wrongly restricted content |
| Routing history | Past announcements of the block, origin ASNs and any hijack or leak reports | Reveals risks that buyers rarely see |
| Registry records | WHOIS or registry objects, abuse contact, reverse DNS delegation | Shows whether ownership and contacts are clean and current |
| RPKI and IRR | Existing ROAs and route objects that may conflict with the new holder | Avoids routing being filtered after the transfer |
Our cleaning process
- Audit: we scan every address in the block against blacklists and reputation sources, and record the routing and registry history.
- Report: you receive a written summary listing each issue, its likely cause and its severity.
- Fix the source: where a listing came from a misconfiguration, such as an open relay or a missing reverse DNS entry, we correct it first, because a delisting request fails if the cause remains.
- Delisting requests: we submit removal requests to each list operator and follow up until they respond.
- Data corrections: we ask geolocation providers to update the location of the block and align registry and RPKI records with the new holder.
- Monitoring: we recheck the block after cleaning and alert you if a new listing appears.
What we can and cannot promise
Each blacklist is run by an independent operator with its own rules, so no broker can guarantee removal or a fixed delay.
- What we commit to: a full audit, a clear report, and every removal request prepared and followed up with the evidence operators ask for.
- What depends on others: the operator's decision and its response time. Some listings clear within hours, others take weeks, and a repeat offender may stay listed longer.
- What we advise: run the audit before signing. If a block has serious problems, the finding can support a price adjustment or a decision to walk away.
Frequently asked questions
Can you check a block before I buy it?
Yes. A pre-purchase audit is the most useful moment to check, because findings can still change the price or the decision.
Is cleaning included in a purchase or a lease?
.
How long does cleaning take?
The audit and report are fast. Delisting depends on each operator, so timing varies from a few days to several weeks.
Can I order cleaning for addresses I already own?
Yes. The service applies to any IPv4 block, whether it came through BRENAC or not.
Can you check a block before I buy it?
Yes. A pre-purchase audit is the most useful moment to check, because findings can still change the price or the decision.
Request an IP audit
Send us the blocks you want to check and we will return a written reputation report.
See also:
- Buy IPv4 Addresses
- IPv4 Leasing & Rental
- Infrastructure Management - IPAM
