What is IMP Spam RBL?
DNS zone: spamrbl.imp.ch
spamrbl.imp.ch is one of the DNSBL zones published by IMP under its antispam.imp.ch project, listing IP addresses observed delivering spam to IMP's mail systems and traps. Like most operator-run lists, it exists first to protect the operator's own users, with public DNS access offered as a courtesy to other administrators.
The listing basis is direct observation: your IP delivered something IMP's filtering classified as spam. Entries are managed on the operator's schedule, generally aging out once the offending traffic stops appearing in their logs.
How serious is a IMP Spam RBL listing?
Small in isolation. Adoption outside IMP's own infrastructure and a set of European mail servers is limited, so a listing rarely explains widespread bounces. Its diagnostic value is the usual one for observation-based lists: something from your IP looked like spam to a real receiving system recently, and corroboration on larger lists should be checked.
Why your IP got listed
Spam delivered to IMP-protected mailboxes or traps
Bulk mail to stale or acquired European lists is the typical trigger for niche regional RBLs like this one.
A compromised account or relay
Third-party spam exiting through your infrastructure is indistinguishable from your own mail at the receiving end.
Inherited IP history
A previous holder's traffic can leave a lingering entry on lists with slow expiry cycles.
How to remove your IP from IMP Spam RBL
Confirm the listing and check corroboration
Verify the hit via our checker, then look at the larger lists in the same report. An IMP-only listing with everything else clean is low urgency; corroborated listings mean a real stream problem.
Stop whatever IMP observed
Audit recent sending to European recipients, prune stale segments, and rule out compromise (credential rotation, outbound queue review).
Wait for age-out, or contact the operator
Entries generally expire once the observations stop. If the listing persists and demonstrably blocks mail you care about, use the contact channels published on antispam.imp.ch (or imp.ch) to request review, stating what was fixed.
Re-check after a week or two
Operator-run lists move on operator time. Confirm the entry has cleared, and treat any relisting as evidence the source is still active.
How long removal takes
Expect passive expiry over days to weeks once the spam stops, and operator-dependent response times for direct review requests. There is no fee and no express lane; there is also rarely a need for one given the list's footprint.
After delisting: the part most guides skip
Getting off IMP Spam RBL removes a block; it does not restore trust. While you were listed, mailbox providers were accumulating their own negative signals about your domain (bounces, spam-folder placements, dropped engagement), and those persist after the listing clears. If placement does not bounce back within a couple of weeks, the domain needs a structured re-warming: reduced volume, genuinely engaged recipients and clean authentication, sustained until providers trust the domain again.
Frequently asked questions
How do I get removed from spamrbl.imp.ch?
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Stop the mail that triggered the observation and the entry will normally age out on its own within days to weeks. For persistent entries, contact IMP through the antispam.imp.ch project pages with a short factual account of what was fixed.
Is an IMP Spam RBL listing serious?
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By itself, no: adoption is limited, so widespread bounces are unlikely to trace to it. Its value is as a signal. Cross-check Spamhaus, SpamCop and Barracuda; if those are clean and this hit stands alone, note it and move on.
Why would a Swiss ISP list my IP?
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Because your IP delivered mail that IMP's filtering classified as spam, to its users or traps. Distance is irrelevant; DNSBLs list whoever their infrastructure observes. The usual root causes are stale list segments or a compromised sender.