TechTheft Blacklist

TechTheft is a private IP-based blocklist and blacklist. Delisting requires the resolution of all open complaints regarding network abuse.

Updated on 17 Jun 2026: We updated this guide with clearer TechTheft investigation steps, abuse contact guidance, and a more precise explanation of private blocklist impact.

Summarize with

Check if you are listed on TechTheft Blacklist

And 143 other blocklists.

Spamhaus

0Spam

Abusix

Barracuda Networks

Cisco

Mailspike

NoSolicitado

SURBL

UCEPROTECT

URIBL

8086 Consultancy

abuse.ro

ALPHANET

Anonmails

Ascams

BLOCKEDSERVERS

Brukalai.lt

Calivent Networks

dan.me.uk

DrMx

DroneBL

EFnet

Fabel

GBUdb

ImproWare

JIPPG Technologies

Junk Email Filter

JustSpam

Kempt.net

Mail Baby

NordSpam

nsZones

Polspam

RV-SOFT Technology

Schulte

Scientific Spam

Spam Eating Monkey

Spamikaze

SpamRATS

SPFBL

Suomispam

System 5 Hosting

Taughannock Networks

Team Cymru

Tornevall Networks

Validity

www.blocklist.de Fail2Ban-Reporting Service

ZapBL

2stepback.dk

Fayntic Services

ORB UK

RedHawk

technoirc.org

TechTheft

Spamhaus

0Spam

Abusix

Barracuda Networks

Cisco

Mailspike

NoSolicitado

SURBL

UCEPROTECT

URIBL

8086 Consultancy

abuse.ro

ALPHANET

Anonmails

Ascams

BLOCKEDSERVERS

Brukalai.lt

Calivent Networks

dan.me.uk

DrMx

DroneBL

EFnet

Fabel

GBUdb

ImproWare

JIPPG Technologies

Junk Email Filter

JustSpam

Kempt.net

Mail Baby

NordSpam

nsZones

Polspam

RV-SOFT Technology

Schulte

Scientific Spam

Spam Eating Monkey

Spamikaze

SpamRATS

SPFBL

Suomispam

System 5 Hosting

Taughannock Networks

Team Cymru

Tornevall Networks

Validity

www.blocklist.de Fail2Ban-Reporting Service

ZapBL

2stepback.dk

Fayntic Services

ORB UK

RedHawk

technoirc.org

TechTheft

Spamhaus

0Spam

Abusix

Barracuda Networks

Cisco

Mailspike

NoSolicitado

SURBL

UCEPROTECT

URIBL

8086 Consultancy

abuse.ro

ALPHANET

Anonmails

Ascams

BLOCKEDSERVERS

Brukalai.lt

Calivent Networks

dan.me.uk

DrMx

DroneBL

EFnet

Fabel

GBUdb

ImproWare

JIPPG Technologies

Junk Email Filter

JustSpam

Kempt.net

Mail Baby

NordSpam

nsZones

Polspam

RV-SOFT Technology

Schulte

Scientific Spam

Spam Eating Monkey

Spamikaze

SpamRATS

SPFBL

Suomispam

System 5 Hosting

Taughannock Networks

Team Cymru

Tornevall Networks

Validity

www.blocklist.de Fail2Ban-Reporting Service

ZapBL

2stepback.dk

Fayntic Services

ORB UK

RedHawk

technoirc.org

TechTheft

Spamhaus

0Spam

Abusix

Barracuda Networks

Cisco

Mailspike

NoSolicitado

SURBL

UCEPROTECT

URIBL

8086 Consultancy

abuse.ro

ALPHANET

Anonmails

Ascams

BLOCKEDSERVERS

Brukalai.lt

Calivent Networks

dan.me.uk

DrMx

DroneBL

EFnet

Fabel

GBUdb

ImproWare

JIPPG Technologies

Junk Email Filter

JustSpam

Kempt.net

Mail Baby

NordSpam

nsZones

Polspam

RV-SOFT Technology

Schulte

Scientific Spam

Spam Eating Monkey

Spamikaze

SpamRATS

SPFBL

Suomispam

System 5 Hosting

Taughannock Networks

Team Cymru

Tornevall Networks

Validity

www.blocklist.de Fail2Ban-Reporting Service

ZapBL

2stepback.dk

Fayntic Services

ORB UK

RedHawk

technoirc.org

TechTheft

Spamhaus

0Spam

Abusix

Barracuda Networks

Cisco

Mailspike

NoSolicitado

SURBL

UCEPROTECT

URIBL

8086 Consultancy

abuse.ro

ALPHANET

Anonmails

Ascams

BLOCKEDSERVERS

Brukalai.lt

Calivent Networks

dan.me.uk

DrMx

DroneBL

EFnet

Fabel

GBUdb

ImproWare

JIPPG Technologies

Junk Email Filter

JustSpam

Kempt.net

Mail Baby

NordSpam

nsZones

Polspam

RV-SOFT Technology

Schulte

Scientific Spam

Spam Eating Monkey

Spamikaze

SpamRATS

SPFBL

Suomispam

System 5 Hosting

Taughannock Networks

Team Cymru

Tornevall Networks

Validity

www.blocklist.de Fail2Ban-Reporting Service

ZapBL

2stepback.dk

Fayntic Services

ORB UK

RedHawk

technoirc.org

TechTheft

What is the TechTheft Blacklist?

The TechTheft Blacklist (bl.techtheft.info) is a private IP-based, DNSBL-style blocklist used internally by its subscribers. It is a composite blacklist, meaning it combines the IP addresses listed in its various sub-zones into one broader zone. The operators caution that using this main combined zone carries a high risk of collateral damage, or blocking legitimate email, and suggest that users consider the individual sub-zones instead when they want narrower filtering.

TechTheft describes its traps as listing any internet asset they come into contact with, which includes:

Email sources and servers
DNS nameservers
Network IP blocks
Website hosts
Virus-infected machines
Web crawling spiders and agents

This blocklist is private and not available for public use. Access is granted by invitation only to trusted parties. For senders, that means a TechTheft listing is usually discovered through SMTP rejection text, a recipient administrator, or a postmaster report rather than a public lookup page.

Who runs the TechTheft Blacklist?

The blacklist is run by an organization called TechTheft. Its stated mission is to combat what it calls "Hi-Technology Theft," including spam, viral attacks, and Distributed Denial of Service (DDoS) attacks. It provides a collaboration point for administrators and hobbyists who want to act against technology abuse.

TechTheft advocates for a very aggressive approach, calling for an "Internet Death Penalty" against sources and supporters of internet abuse. Its policy is to block the offending IP and the supporting infrastructure connected to it, such as DNS, mail hosts, and web hosts. This hardline policy comes from its view that earlier anti-spam systems such as MAPS and SPEWS were too slow or lenient against modern threats.

How to investigate a TechTheft listing

Because TechTheft is private, do not treat the absence of a public lookup result as proof that there is no listing. Start with the evidence from the affected delivery path and work backward to the infrastructure named in the rejection or complaint.

Capture the SMTP rejection text, recipient domain, sending IP, timestamp, and any reference to bl.techtheft.info.
Check the sending IP, rDNS, HELO or EHLO name, DNS nameservers, web host, and adjacent netblock for a connection to the complaint.
Review mail server logs for compromised accounts, open relays, malware, forwarded spam, high bounce bursts, or traffic from systems that should not send mail.
Confirm that abuse contacts work for the IP's domain, the sending domain, and the network owner, then keep replies tied to the complaint trail.
Use DMARC aggregate data to separate authenticated legitimate mail from spoofed traffic. Suped's product can help group SPF, DKIM, and source IP patterns during that review.

How to get delisted from the TechTheft Blacklist

The delisting process for this blacklist is based on resolving abuse complaints. An IP is listed because an abuse-related complaint was sent and has not been resolved. Once all active complaints associated with the IP address and related infrastructure are fixed, the listing is automatically removed.

Before requesting delisting, make sure the abuse contact works and that the team monitoring it can respond quickly. TechTheft specifies the following:

Set up a functioning abuse@yourdomain.example address for both the IP address's domain and the sending domain.
Resolve every active complaint sent to that address. The listing is removed only after the underlying abuse issue has been fixed.

TechTheft states that you can find open complaints related to your IP on its site, which is the first step to resolving the issues. It does not provide a public delisting form. Removal depends on fixing the problems that led to the abuse reports.

What is the impact of a TechTheft listing?

The overall impact of being on the TechTheft blacklist is usually limited because the list is private and available only to invited subscribers. It does not have the same broad footprint as public blocklists used by many mail servers.

The impact can still be severe at a network that subscribes to it. A listed IP, nameserver, mail host, web host, or netblock can trigger blocking for that recipient environment, including SMTP connection rejections or message filtering before the mail reaches the inbox.