How to remove your IP from IMP Spam

IMP Spam is ImproWare's IP blocklist of addresses seen sending spam. Here is what a listing means and how to get off it.

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What it is

The list, in plain terms.

IMP Spam is the DNS blocklist published at the zone spamrbl.imp.ch by ImproWare AG, a Swiss provider based in Pratteln. It lists IPv4 addresses that ImproWare captured sending spam. Receivers query the zone during the SMTP conversation and defer or reject mail from any IP it returns.

ImproWare runs the list alongside two companions — dnsrbl.imp.ch, assembled from spamtrap hits, and uribl.imp.ch, which lists domains that appear inside spam rather than the IPs that sent it. The same zones are also published under the swinog.ch domain. IMP Spam is the IP-reputation list, so a listing flags your sending server, not the domain in your message.

It is a smaller list than the large operators, but several mail platforms and blocklist aggregators still consult it, so a listing can quietly cause bounces and deferrals at a subset of receivers until you clear it.

Why you get listed

What a listing on IMP Spam means.

Spam reached ImproWare Your IP was seen sending mail that ImproWare classified as spam. This is the direct cause: the address appears in the spam ImproWare captured, so it is added to spamrbl.imp.ch.

A compromised host An exploited or malware-infected machine on the IP, or a hijacked mailbox behind it, is emitting spam without your knowledge. The listing reflects the traffic, not your intent.

An open relay or misconfiguration A server that relays mail for anyone, or a broken authentication setup, lets third parties push spam through your IP. ImproWare sees the spam and lists the address.

Bulk sending that looks like spam Large mailings with poor list hygiene, missing opt-in or weak authentication can trip the filters even when you consider the mail legitimate.

How to get removed

Delisting, in order.

Removal is free. Fix the cause first — a listing you clear without a fix comes straight back.

1 Confirm the listing. Enter your IPv4 address in the "Check your IPv4 Address" box at antispam.imp.ch. If the address is listed, the result page says so and links through to the entry details and a delisting request form.
2 Fix the cause first. Find and stop the spam before you ask for removal: clean the infected host, close the open relay, secure the abused mailbox, or correct the bulk-sending setup. ImproWare warns that requesting delisting without removing the cause makes each subsequent request harder to approve.
3 Submit the free removal request. On the result page, use the delisting form. Provide the IPv4 address, a contact email and a short explanation, in English only, of what you fixed. Removal is 100% free — ImproWare charges nothing.
4 Wait for processing, and do not resubmit. Most requests are handled within 48 hours. You cannot submit a removal for the same IP more than once a week, so send one clear request and wait rather than repeating it.
5 Re-check before you resume sending. Once the request is processed, look the IP up again at antispam.imp.ch to confirm it is no longer listed before you ramp your sending back up.

The official route

Straight to the source.

Removal happens on IMP Spam's own tool — never through a paid service.

IMP Spam removal tool ↗

How long it takes

Most removal requests are processed within about 48 hours. You may only submit one removal request per IP address per week, so wait for the outcome rather than resubmitting. If the underlying spam has not stopped, expect the listing to return and future requests to be treated with more scrutiny.

Common questions

About IMP Spam, specifically.

What is spamrbl.imp.ch and who runs it? It is the IMP Spam DNS blocklist operated by ImproWare AG in Switzerland. It lists IPv4 addresses that ImproWare captured sending spam, and receivers query it to reject or defer mail from those IPs.

How do I remove my IP from the IMP Spam blocklist? Check the IP at antispam.imp.ch. If it is listed, the result page shows a delisting request form — provide the IP, an email address and an English explanation of the fix. First make sure the spam has actually stopped.

Does ImproWare charge to delist my IP? No. IP removals for the ImproWare dnsbl services are 100% free. Any third party offering to remove an IMP Spam listing for a fee is a scam — no outside service can influence an ImproWare removal.

How long does IMP Spam removal take? Most removal requests are processed within about 48 hours. You can only submit one request per IP per week, so send a single clear request and wait rather than resubmitting.

Why do I keep getting relisted? Because the source of the spam is still active. ImproWare warns that repeatedly requesting delisting without removing the cause makes each request harder to approve. Clean the compromised host, close the relay or fix the sending setup, then delist.

I do not run a mail server — do I need to do anything? ImproWare states that if you are not an email administrator and do not own or manage your own mail server, you should never have to remove yourself from this list. Removal is for the operator who controls the sending IP.

The bounce behind the listing.

554 5.7.1 message rejected → The permanent bounce a listing most often triggers — what it means and how to clear it. 550 5.7.1 blocked → A rejection on reputation grounds — usually the same listing, seen from the sender side. Blacklist checker → Re-check your domain and every sending IP once the cause is fixed.

Do not fix it blind.

See every list you are on and every authentication problem behind the listing in one 40-second check — then let monitoring tell you the day a listing comes back.

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