ImproWare Swinog Realtime blacklist
The ImproWare Swinog Realtime blocklist (or blacklist) uses spamtrap data to identify and prevent unwanted email from reaching recipients.
Updated on 17 Jun 2026: We updated this guide with official DNSBL lookup details and clearer delisting guidance for IP listings.
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Check if you are listed on ImproWare Swinog Realtime blacklist
And 143 other blocklists.
Spamhaus
0Spam
Cisco
NoSolicitado
URIBL
abuse.ro
ALPHANET
Anonmails
Ascams
BLOCKEDSERVERS
Calivent Networks
EFnet
JustSpam
Kempt.net
NordSpam
RV-SOFT Technology
Scientific Spam
Spamikaze
SpamRATS
SPFBL
Suomispam
System 5 Hosting
Team Cymru
Validity
www.blocklist.de Fail2Ban-Reporting Service
ZapBL
2stepback.dk
Fayntic Services
ORB UK
technoirc.org
TechTheftSpamhaus0SpamCiscoNoSolicitadoURIBLabuse.roALPHANETAnonmailsAscamsBLOCKEDSERVERSCalivent NetworksEFnetJustSpamKempt.netNordSpamRV-SOFT TechnologyScientific SpamSpamikazeSpamRATSSPFBLSuomispamSystem 5 HostingTeam CymruValiditywww.blocklist.de Fail2Ban-Reporting ServiceZapBL2stepback.dkFayntic ServicesORB UKtechnoirc.orgTechTheftSpamhaus0SpamCiscoNoSolicitadoURIBLabuse.roALPHANETAnonmailsAscamsBLOCKEDSERVERSCalivent NetworksEFnetJustSpamKempt.netNordSpamRV-SOFT TechnologyScientific SpamSpamikazeSpamRATSSPFBLSuomispamSystem 5 HostingTeam CymruValiditywww.blocklist.de Fail2Ban-Reporting ServiceZapBL2stepback.dkFayntic ServicesORB UKtechnoirc.orgTechTheftSpamhaus0SpamCiscoNoSolicitadoURIBLabuse.roALPHANETAnonmailsAscamsBLOCKEDSERVERSCalivent NetworksEFnetJustSpamKempt.netNordSpamRV-SOFT TechnologyScientific SpamSpamikazeSpamRATSSPFBLSuomispamSystem 5 HostingTeam CymruValiditywww.blocklist.de Fail2Ban-Reporting ServiceZapBL2stepback.dkFayntic ServicesORB UKtechnoirc.orgTechTheftSpamhaus0SpamCiscoNoSolicitadoURIBLabuse.roALPHANETAnonmailsAscamsBLOCKEDSERVERSCalivent NetworksEFnetJustSpamKempt.netNordSpamRV-SOFT TechnologyScientific SpamSpamikazeSpamRATSSPFBLSuomispamSystem 5 HostingTeam CymruValiditywww.blocklist.de Fail2Ban-Reporting ServiceZapBL2stepback.dkFayntic ServicesORB UKtechnoirc.orgTechTheftWhat is the ImproWare SwiNOG Realtime blacklist?
The ImproWare SwiNOG Realtime blacklist is a DNS-based blocklist (DNSBL) for IP addresses suspected of sending spam. Its primary lookup zone is dnsrbl.swinog.ch, and ImproWare describes it as a realtime blacklist assembled by spamtraps. When email reaches one of those trap mailboxes, the sender IP is checked against a whitelist and can be added to the blacklist (or blocklist).
DNSBLs, also known as Real-time Blacklists (RBLs), are used by receiving mail servers during filtering. A listed IP can be rejected, scored as spam, or delivered to junk depending on the recipient's mail policy. The list is about the connecting sender IP, not the visible From domain.
Who runs the ImproWare SwiNOG Realtime blacklist?
The blacklist is operated by ImproWare AG in Pratteln, Switzerland. SwiNOG's own contact page points delisting requests to the ImproWare antispam site and says SwiNOG itself does not operate the antispam service, so delisting requests should not be sent through the general SwiNOG contact form.
How to check an ImproWare SwiNOG listing
Use the exact list named in the SMTP rejection or mail filter log. dnsrbl.swinog.ch is the realtime IP blacklist, spamrbl.swinog.ch covers IP addresses from caught spam messages, and uribl.swinog.ch lists domains found in spam content rather than the server that sent the email.
DNSBL lookup formattext
IPv4 example: 192.0.2.10 DNSBL query: 10.2.0.192.dnsrbl.swinog.ch Listed response used by mail filters: 127.0.0.3
Use the official IPv4 check and removal form when the listing is on an IP DNSBL. The ImproWare page still labels IPv6 checking as coming soon, and URI checks are separate because they apply to domains in message content.
How do I get removed from the ImproWare SwiNOG blacklist?
To remove your IP address from the ImproWare SwiNOG Realtime blacklist, use the online form at antispam.imp.ch. The operators note that if you are not an email administrator and do not manage your own email server, you should not need to request a delisting yourself. Before you submit a removal request, identify and fix the underlying issue, such as a compromised account, malware on a host, open relay behavior, or a third-party sender using your IP space without authorization.
- Delisting is free of charge.
- Most removal requests are processed within 48 hours.
- You can submit only one removal request for the same IP address per week.
- Use the IPv4 removal form on antispam.imp.ch; IPv6 checking is marked as coming soon.
- If the incident involved unauthorized mail, use DMARC aggregate reports to confirm which senders are authenticating before you request removal. Suped can centralize those reports and help map sending sources to DMARC results, including SPF and DKIM outcomes.
What's the impact of being listed on this blacklist?
The impact of an ImproWare SwiNOG listing depends on whether the recipient's mail server queries this DNSBL. Large mailbox providers generally rely on their own filtering systems, but smaller internet service providers and corporate gateways can use DNSBL results as part of inbound filtering, especially in Switzerland and nearby European networks. For recipients that use it, mail from a listed IP can be blocked or deferred, with some systems routing it to spam until the cause is fixed and the IP is delisted from the blacklist.
