- Operator
- Proofpoint (former)
- Zones
- dnsbl.sorbs.net, spam.dnsbl.sorbs.net, new.spam.dnsbl.sorbs.net
- Lists
- IP addresses
- Status
- Retired. Service shut down on 5 June 2024.
- Severity
- None: the list no longer exists
- Lookup
- None
- Removal
- none (service decommissioned 2024-06-05)
- Cost
- n/a
- Turnaround
- n/a
- Auto-expiry
- n/a
What is SORBS (all zones)?
SORBS (the Spam and Open Relay Blocking System) ran from 2002 and listed open relays, proxies, spam sources and dynamic address space across a family of zones under dnsbl.sorbs.net. Proofpoint acquired it in 2011 and, after years of intermittent availability, closed it in 2024. On 5 June 2024 the zones stopped serving listing data. There is no successor list and no archive of old listings to be removed from.
Plenty of blacklist checkers were built with the SORBS zones hard-coded and never updated. When they query spam.dnsbl.sorbs.net today they get an empty answer or an error, and some render that as listed or as check failed. Neither is information about your IP. A bounce message that names SORBS means the receiving server still queries the retired zone and treats an error as a block, which is that server's misconfiguration.
How serious is a SORBS (all zones) listing?
None. There is no list to be on. The only residual effect is a receiver that never removed the dead zone from its filter and treats the error as a block, and that is fixed on their side, not yours.
If a checker still shows it
Plenty of blacklist checkers were built with the SORBS zones hard-coded and never updated. When they query spam.dnsbl.sorbs.nettoday they get an empty answer or an error, and some render that as “listed” or “check failed”. Neither is information about your IP. A bounce message that names the list means the receiving server still queries the retired zone and treats an error as a block, which is that server's misconfiguration; there is nothing you can delist.
What to check instead
The lists that decide placement today are the ones large providers and gateways actually query. Start with Spamhaus ZEN and the Spamhaus DBL for the domain itself, then Barracuda and SpamCop. The free blacklist checker queries the active lists in one pass. If every list is clean and mail still lands in spam, the cause is reputation or authentication rather than a listing.
Frequently asked questions
Is SORBS still active?
No. Proofpoint, which had owned SORBS since 2011, shut the service down on 5 June 2024. The DNS zones (dnsbl.sorbs.net, spam.dnsbl.sorbs.net and new.spam.dnsbl.sorbs.net) no longer return listing data.
A blacklist checker says I am listed on SORBS. What do I do?
Nothing, because there is nothing to be listed on. A checker that reports a SORBS listing, or a SORBS check failure, in 2026 is querying a dead zone and reporting the empty or error response. Ignore the row and check the lists that still decide placement: Spamhaus ZEN and DBL, Barracuda, SpamCop and the others our free checker queries.
How do I get removed from SORBS?
You cannot, and you do not need to. There is no removal form and no operator to write to. Any service offering SORBS delisting today is selling removal from a list that no longer exists.
Could a SORBS listing still block my mail?
Only if a receiving server still queries the retired zone and treats an error as a block, which would be a misconfiguration on the receiver's side, not a reputation problem on yours. If mail is bouncing with a SORBS reference, that server's administrator needs to remove the zone from their filter.
Record checked against the operator's site on ; the whole set was last reviewed on . Cells that say undocumented or not found are gaps in the operator's own material, left as they are.