Barracuda Blacklist Removal (BRBL)

Short answer: confirm the IP is listed on b.barracudacentral.org (return code 127.0.0.2), stop sending from it, fix what caused the listing, then submit Barracuda Central's free removal request with the IP, a working email and phone number, and a specific explanation of the cause and the fix. Most requests clear within 12–24 hours. Requests that just say "please delist" are routinely ignored.

Is it really Barracuda? The symptom checklist

Barracuda listings have a recognisable shape, because the list is used by a specific kind of receiver: Barracuda Email Security Gateway and Email Gateway Defense deployments in front of company mail servers.

• Gmail, Outlook.com and Yahoo deliver normally, but a wave of company domains suddenly bounces or goes silent. Consumer providers don't use BRBL; corporate gateways do.
• Bounces cite Barracuda by name: 554 ... Service unavailable; Client host [IP] blocked using b.barracudacentral.org or ... blocked using Barracuda Reputation. Some gateways return a generic 550 5.7.1 with a link to barracudacentral.org.
• The affected recipients cluster by company, not by individual — everyone at a given domain bounces, because the gateway blocks at the connection.
• The listing is on an IP, never a domain. BRBL is an IP reputation list. If your sending IP belongs to Google Workspace, Microsoft 365 or an ESP, the listed IP is theirs (see below).

Run the checker above with your sending domain. It resolves the domain's IPs and queries b.barracudacentral.org for each one alongside nine other lists. A Barracuda hit shows the exact IP and return code.

Step 1 — Verify the listing and identify the IP

1. Take the IP from the bounce message — the one in square brackets after "Client host". That is the IP the receiver saw, which may not be the IP you expected.
2. Query it: the checker above, or a manual DNS lookup of the reversed IP under b.barracudacentral.org. A 127.0.0.2 answer confirms the listing; no answer means not listed.
3. Establish whose IP it is. Reverse DNS usually tells you: mail-xx.google.com means Google Workspace, *.outbound.protection.outlook.com means Microsoft 365, and *.sendgrid.net, *.mailgun.org, *.amazonses.com and so on mean an ESP. A hostname you set up yourself means it is your own server.

If the IP belongs to Google or Microsoft: you cannot request removal (Barracuda will not accept it from you), and their outbound IPs are rarely listed for long — the listing usually clears on its own within a day as their reputation systems act. Your action is to make sure your own domain reputation and authentication are clean so you aren't the customer whose traffic caused it. If the IP belongs to an ESP: open a ticket; ask whether the pool is shared and whether they will move you or handle the appeal. If it's your own server: continue with the steps below.

Step 2 — Find the cause before requesting removal

Barracuda's reputation system combines spam-trap hits, message-content signals and complaint data from its gateways with sending-pattern analysis. The removal form asks what caused the listing, and a credible answer is what gets a request processed. The usual causes for outbound and SDR infrastructure:

Cause	How to recognise it	The fix Barracuda wants to hear
Volume spike from a new IP or domain	Listing within days of standing up new infrastructure or a big sequence launch	Warm-up schedule; daily caps per mailbox and per IP
Spam-trap hits from a bad list	Listing follows a list import; high unknown-user bounce rate on the same send	List source removed; verification before every import
Compromised mailbox or web form	Outbound volume you didn't send; unfamiliar subjects in the mail queue	Credential rotated, form secured, queue purged
Missing reverse DNS or authentication	rDNS doesn't match HELO; SPF/DKIM failing in headers	Matching PTR; SPF, DKIM, DMARC passing
Shared-IP contamination	Your own volume is small and clean; ESP pool has other listings	Pool move via provider; dedicated IP once volume justifies it
Content triggers	Listing coincides with a template change (shorteners, tracking domains, attachments)	Remove shorteners, use a branded tracking domain, drop attachments

Check reverse DNS and authentication even if you think they're fine. The domain grader shows SPF, DKIM, DMARC and MX status in one pass, and a failing item is the single most common reason a Barracuda appeal is weak.

Step 3 — Submit the removal request

Barracuda Central's removal request form is on barracudacentral.org under the Reputation System section. There is one form, it is free, and there is no expedited option.

1. IP address — the listed IP, exactly as it appears in the bounce. One IP per request.
2. Email address — use a monitored mailbox on your own domain, not a free webmail address. Barracuda may reply with questions, and a reply from a consumer address weakens the request.
3. Phone number — required. It is part of how Barracuda separates real organisations from throwaway infrastructure.
4. Reason for removal — the field that decides the outcome. Write two to four specific sentences: what the IP is used for, what caused the listing (from the table above), what you changed, and when. Example shape: "This IP sends outbound mail for <company>'s sales team via <platform>. On <date> a newly imported prospect list produced a spike in unknown-user bounces; we've removed that list source, added verification before import, and capped daily volume at <n> per mailbox. SPF, DKIM and DMARC pass and rDNS matches."
5. Submit and note the time. Don't submit duplicate requests; a second request for the same IP before the first is processed only slows things down.

What not to write: "we are a legitimate company", "we never send spam", or anything that argues with the listing rather than explaining it. The reviewers see the trap data; the request that acknowledges a plausible cause is the one that gets processed.

How long does Barracuda removal take?

Situation	Typical time
First listing, specific reason given, authentication clean	12–24 hours
Request with no reason or a boilerplate reason	Often never processed — resubmit with detail
Repeat listing within 30 days	24–72 hours; may require the cause to be visibly resolved first
IP belongs to Google/Microsoft/ESP	Not yours to request; typically self-clears within a day as the provider acts

After Barracuda confirms removal, gateways still need to refresh their cached lookups. Allow a few hours before judging whether bounces have stopped, and resume sending gradually — half your previous daily volume for the first week.

If you keep getting re-listed

A second Barracuda listing within weeks means the cause wasn't fixed, and each repeat makes appeals slower. The usual culprits, in order:

• Volume resumed at full speed. Ramp back over a week, not a day. Barracuda's pattern analysis weights sudden changes heavily.
• The list source is still feeding your CRM. Removing the addresses that bounced doesn't remove the vendor that produced them. Verify at import, every time.
• The shared pool is the problem. If you're on a shared ESP pool that keeps being listed, move pools or move providers; you can't appeal your way out of a neighbour's behaviour.
• Warm-up was skipped for new mailboxes. Each new mailbox on an IP is a fresh sending pattern. Warm them individually before adding them to sequences.

Preventing the next listing

• Reverse DNS that matches your HELO/EHLO name, on every sending IP.
• SPF, DKIM and DMARC passing on every stream — check all four at once.
• Written ramp schedules and per-mailbox daily caps for new domains and IPs.
• List verification before import; no purchased or scraped data without it.
• Branded tracking domains instead of shorteners; no attachments in cold outreach.
• Blacklist sweeps every few hours with alerts on change, so a Barracuda listing is found on day one — not at the end of the quarter when someone asks why corporate replies dried up.

FAQ

Is Barracuda blacklist removal free?

Yes. Barracuda Central's removal form is free and there is no paid or expedited path. Anyone charging for Barracuda delisting is filling in the same form.

Can I check the Barracuda list myself?

Yes — the zone is b.barracudacentral.org, queried with the IP octets reversed. A 127.0.0.2 answer means listed. The checker at the top of this page does the lookup for every IP your domain resolves to, plus nine other lists.

Does a Barracuda listing affect Gmail or Outlook.com delivery?

Not directly. Consumer providers use their own reputation systems, not BRBL. But the behaviour that caused the Barracuda listing usually hurts consumer-provider reputation in parallel, so fix the cause rather than just the listing.

My ESP says the listed IP is shared — what now?

Ask for a pool move and confirm your own domain is clean on domain-based lists (Spamhaus DBL, SURBL). If pool listings recur, that is a provider-selection signal. See the master removal guide for the IP-versus-domain diagnosis.