Barracuda Networks (Barracuda Central) · Primarily IP addresses. The DNSBL zone (b.barracudacentral.org) lists sending IPs; Barracuda Central separately maintains URL/domain reputation data used by its appliances, but the public BRBL DNSBL that mail servers query is IP-based.
Barracuda Reputation Block List (BRBL)
The BRBL is a free, public, real-time DNS-based blocklist (DNSBL) that Barracuda Networks has maintained since 2008, queried at the zone b.barracudacentral.org. It catalogs IP addresses that Barracuda's sensor network and spam traps associate with spam or abuse, and feeds the spam-filtering decisions of Barracuda's email security appliances/gateways. It is moderately aggressive: listings are generated automatically from observed sending behavior (spam traps, volume/abuse signals) rather than manual curation, so a single compromised host or trap hit can get an IP listed quickly.
Why you get listed
- The IP hit one of Barracuda's spam traps (mail sent to a dormant/never-opted-in address)
- A compromised server, CMS, or device on the IP is sending spam in the background
- Running an open relay or open proxy that allows third-party mail
- A sudden spike in send volume or other patterns that look like a spam run
- Sending from an IP with poor sending hygiene (missing/inconsistent rDNS, high complaint or bounce rates)
- Shared-IP contamination - a neighbor on a shared/ESP IP triggered the listing
Impact
Used by Barracuda's large installed base of email security gateways/firewalls, so a listing mainly hurts delivery to organizations (often corporate/B2B) that run Barracuda appliances rather than the big consumer mailbox providers like Gmail or Outlook.com. For B2B senders the impact can be significant because many enterprises filter inbound mail through Barracuda; mail from a listed IP is blocked or heavily penalized at those recipients. It is one of several reputation signals, not a universal block, so impact is concentrated at Barracuda-protected domains.
How to delist from Barracuda Reputation Block List (BRBL)
- Confirm the listing first: look up your sending IP at the Barracuda lookup tool - a 'Poor' rating (or a 127.0.0.2 answer from b.barracudacentral.org) means you are listed.
- Find and fix the root cause BEFORE requesting removal: stop the spam source, patch/clean any compromised server or CMS, close any open relay/proxy, scrub your lists, and fix authentication/rDNS. Requesting removal without fixing the cause almost always results in immediate relisting.
- Submit the official removal request form with your mail server's IP address, a valid email address, and a phone number; include a clear, specific reason describing the root cause and how you resolved it (a documented explanation is reviewed and processed faster).
- Submit only once and wait - Barracuda states removal requests are typically investigated and processed within about 12 hours when a valid explanation is provided. Do NOT submit duplicate requests; incomplete or duplicate submissions are disregarded.
- If the form fails or the listing persists, contact Barracuda support (the email security helpdesk) and ask them to open a ticket for your IP removal.
- Monitor: re-check the lookup tool after processing, and keep sending volume/hygiene clean so the automated system does not relist the IP.
Good to know
- Removal is a MANUAL, reviewed process (typically processed within ~12 hours when a valid explanation is given) - it does not auto-expire on a fixed timer, so you must actively submit the removal form; ignoring it can leave the IP listed.
- Submit the removal request only once: Barracuda disregards incomplete and duplicate submissions, and a vague reason gets deprioritized versus one documenting the fixed root cause.
- Requesting removal before fixing the underlying spam source almost always leads to fast relisting, which can extend the effective listing period.
- To actually QUERY the BRBL DNSBL (b.barracudacentral.org) you must register your DNS resolver's IP with Barracuda (free) - it is not openly queryable like some other DNSBLs; the web lookup tool at barracudacentral.org/lookups, however, needs no registration.
- It is an IP-reputation list, not a policy list - unlike Spamhaus PBL (a policy list of dynamic/residential ranges removed via a self-service exclusion), BRBL delisting is the single manual removal-request form regardless of why the IP was listed.
Stay off the lists in the first place.
Most listings trace back to volume spikes, bad lists, and cold domains. Scheduler Zero warms your domains, paces sending, and keeps your lists clean so you build reputation instead of blacklisting yourself.