GBUdb Truncate (Message Sniffer) is a IP blocklist published at gbudb.com. When you're listed, mail servers that consult GBUdb Truncate (Message Sniffer)will block, defer, or spam-folder your messages — so fixing it matters for deliverability. Here's why it happened and exactly how to get off.
Why you got listed
GBUdb Truncate (Message Sniffer) listings almost always trace back to one of these:
A burst of spam or malware from your IP skewed its statistics
Most commonA burst of spam or malware from your IP skewed its statistics. This is the most common trigger for a GBUdb Truncate (Message Sniffer) listing — address it first.
A compromised account or open relay sending in volume
CommonA compromised account or open relay sending in volume.
Very low legitimate volume from an IP that mostly sent spam
Less commonVery low legitimate volume from an IP that mostly sent spam.
How to get delisted
Delisting that lasts has two parts: fix the root cause, then request removal. Skip the first part and you'll be re-listed almost immediately.
- 1
Find and stop the source
Identify what triggered the listing — a compromised mailbox, a script or web form being abused, a poor-quality list, or a misconfigured mail server. Check your outbound logs for unusual volume and secure any account that looks compromised (rotate passwords, enable MFA, revoke stale API keys).
- 2
Fix the underlying issue
GBUdb is fully automatic and self-correcting — it has no manual removal. Once you stop the spam and send clean traffic, your IP's statistics recover and the listing clears on its own, usually within days.
- 3
Confirm your authentication is solid
Make sure SPF, DKIM, and DMARC are all passing before you ask for removal — a clean authentication setup is part of demonstrating you're a legitimate sender. Run a free EmailHealth check to confirm.
- 4
Submit a removal request at gbudb.com
Go to
gbudb.com, look up your IP to confirm the listing and its stated reason, and use their removal/delisting form. Many listings here also expire on their own once the cause stops.
Stay off it for good
- Keep your list clean — remove hard bounces and never mail purchased or scraped addresses
- Authenticate every sending source with SPF, DKIM, and DMARC
- Monitor your domain so you catch a new listing within a day, not after customers complain
EmailHealth can monitor your domain daily and alert you the moment a blacklist listing (or any other deliverability change) appears.