Why is my IP blacklisted, and how do I get it removed?

Your IP address is blacklisted when a list operator has seen it send spam or attacks, or has put its range on a list of addresses that should not send mail directly. Three different things share the name: mail blocklists that decide whether your email gets through, abuse databases that record attacks, and fraud scores that rate any address. Each one has its own removal path. Every path starts with fixing the cause, because a listing that is confirmed again comes back.

#Which kind of blacklist is my IP on?

Mail blocklists began in 1997 as a list of addresses that had sent spam. The IETF later documented how mail servers query them over DNS (RFC 5782). Abuse databases collect reports of attacks such as brute force logins and scans. Fraud scores, FFraud's among them, rate any address from 0 to 100 using abuse records, VPN and proxy detection and the network around it (how we score).

The message that warned you may name the list. A bounce from Microsoft 365, for example, reads 550 5.7.606-649 Access denied, banned sending IP and gives the address where you ask for removal (Microsoft Learn). A blacklist checker shows which lists hold your address.

#Why was my IP address blacklisted?

A device on your network sends spam or attacks

This listing points to a real problem on your side. Spamhaus describes its Exploits Blocklist (XBL) as addresses that are legitimate but "have been hijacked to use by third-party exploits" (Spamhaus, read October 23, 2026). The device can be a phone: Spamhaus once described a grandmother listed because of "a third-party proxy silently spewing out spam from her smartphone" (Spamhaus, March 2021). The FBI warned in June 2025 that infected streaming boxes, projectors and picture frames open home networks to criminals.

Home lines carry much of this. In a random sample of 240 addresses from FFraud's list, 150 (62.5 percent) were residential connections and 88 were data center addresses (FFraud API, October 23, 2026).

Your home line is on a policy list

Spamhaus's Policy Blocklist (PBL) holds end-user ranges "from which email should never be sent directly to the final destination" (Spamhaus). The addresses on it are not necessarily bad, Spamhaus says; they should simply hand their mail, with a login, to a mail server that delivers it. Spamhaus calls a PBL listing normal and asks for removal requests only from people who run a mail server on that address.

Your mail server or website was abused

Spamhaus builds its Combined Spam Sources list (CSS) automatically from addresses "involved in sending low-reputation email" (Spamhaus). Its triggers include unsolicited mail, poor list hygiene, and malicious mail sent through compromised accounts or content management systems. A hacked website or a stolen mailbox password can be enough.

Someone used the address before you

Hosting and cloud addresses move from customer to customer: Amazon Web Services returns released addresses to its pool (AWS docs). The IETF's guide for list operators notes that listings "can exist after the listed entity has putatively changed ownership" (RFC 6471). A new tenant can inherit a listing on the first day.

You share the address

On a shared address, one spammer gets everyone listed. RFC 6269 says that blacklisting a spammer behind carrier-grade NAT restricts mail for "all other subscribers sharing that address" (RFC 6269, section 13.3). VPN exits, office networks and shared hosting work the same way.

#How do I check which lists have my IP?

1. Find your public address with what is my IP, so you check the address the internet sees.
2. Read the bounce or the block message. Large mail providers name the list and its removal page, as Microsoft's bounce does.
3. Check the mail lists with each operator's own lookup. Spamhaus runs a free checker that detects your address and shows its listings in the order you must remove them.
4. Check FFraud's record with the IP blacklist check: whether the address is listed, what it was caught doing, when it was last seen and how much of its /24 is flagged.
5. Read the reports with the IP abuse check: what the address was reported for, how often, and how much weight the reports carry.

#How do I get my IP removed from a blacklist?

Fix the cause first. Clean or unplug the infected device, change the stolen passwords, patch the website, and stop any bulk mail. Spamhaus tells listed users what to do before they ask for removal, to keep them from being listed again.

Spamhaus

• SBL: only your internet provider's abuse team can ask Spamhaus to remove it, and no other Spamhaus listing comes off first.
• XBL and CSS: one request in Spamhaus's checker covers both. XBL listings also expire on their own once the bad behavior stops.
• PBL: ask only if you run a mail server on that address. Otherwise the listing is normal for a home line.

That order comes from Spamhaus's own article of March 4, 2021. When Spamhaus cannot remove a listing at once, it opens a ticket with its delisting team.

Microsoft 365 and Outlook.com

For a bounce with a code from 5.7.606 to 5.7.649, use Microsoft's delist portal at sender.office.com. Microsoft says removal can take up to 24 hours or longer. For code 5.7.511, forward the bounce to [email protected], and Microsoft replies within 48 hours. Outlook.com, the consumer service, has its own form (Microsoft Learn, updated January 28, 2026).

Abuse databases

AbuseIPDB's FAQ gives no removal procedure. It says its rating comes from reports and their age, that all report weights decay with time, and that ratings are recalculated daily (AbuseIPDB FAQ, read October 23, 2026). CrowdSec offers a removal form for the list it shares with its community. That form cannot lift a ban that one CrowdSec user set on their own server (CrowdSec removal page, 2024).

FFraud

FFraud lists an address only after at least two independent confirmations (how we score). If a listing is wrong, or the address is clean now, ask for a review. A person checks it against our honeypot sensors and community reports. A false positive leaves the next open data build within a day or two.

#Will the listing expire on its own?

Many lists let listings lapse. The IETF's guide says listings "SHOULD be considered temporary" and should expire unless the reasons for them remain (RFC 6471). Spamhaus's XBL expires once the behavior stops, and AbuseIPDB's ratings decay as reports age.

FFraud keeps a confirmed address's score, because attackers rest their servers between campaigns. Its API adds a recent_abuse flag for abuse confirmed in the last 30 days (API reference). FFraud's suggested policy blocks critical scores, and blocks high scores only while that flag is on.

Two in three sampled addresses had abuse confirmed within the previous day. 37 of 240 (15 percent) had none in the last 30 days. Of those 37, 29 still scored critical, which the suggested policy blocks either way; the other 8 would get a challenge instead of a block. None was older than a year.

#Questions people ask