Q & A

Verify DNSBL Listing

Enter the suspected IP address to check the status in our DNSBL's.

If you are listed:

  1. Fix the problem.
  2. Create an account and verify your contact details

Q) Is this the FusionZero DNSBL?

A) Yes. FusionZero was rebranded to 0spam some years ago but many of the older configurations still use FusionZero.

Q) My email was blocked by 0spam, why?

A) 0spam does not block emails, we provide a report on senders based on spam trap triggers. Mail servers may be configured to bounce, delete or place mail that is flagged by 0spam in a spam folder.

Q)Why is my email blocked?

A) Email may have been blocked based on its 0spam reputation by an email provider that you sent to. You should contact your IT or email provider in order to resolve the listing.

Q) How do I unblock my email address?

A) 0spam does not block or list by email address, our services list reputation codes based on IP or URLs.

Q)What blacklists am I on?

A) You can search the full DNSBL here: Full DNSBL Check

Q)Why is the IP of my [large provider name] listed on 0spam?

A) We do not offer any special treatment based on size of organization.

Our system works in the following way:

  1. We have several methods for detecting spam emails with a greater than 99.997% accuracy, including:
    • Email sent to our spam traps
    • Flagged several times by our network users as spam
    • Machine learning algorithms identify email as spam.
    • list removal request are ignored
  2. The sending network is notified that they are a spam source and they need to resolve the issue.
  3. The IP is listing in our database with date/time and email subject, which can be queried from the main page at 0spam.org.
  4. They can remove the IP at any point at no charge here or a verified IP owner can setup a Notify services account which grants them the ability to have a 24 hour buffer in order to manage IP's before they are listed in our public DNSBL.

The biggest issue is that many larger email providers allow free users to share server IPs with paid users, so the free users abusing their network prevent the paid users from sending email because the source IP is a spam source.

It is highly recommended that you find a provider that does not offer free email services or if they do, limits them considerably to make using their network for spam unappealing or they use outbound filters to stop spammers on their network which will prevent your valid emails as being flagged as spam.

Q) How is the 0spam project supported?

A) 0spam.org is funded in the following ways:

  • By donation.
  • Intelligent detection services which help service providers identify spam before it reaches your inbox.
  • IP listing Notification Services.

Q) Is this dnsbl service free?

A) Yes. DNSBL service and removals are 100% for free for all uses; commercial, non profit and personal. We do have a paid notification service for IP providers that wish to remain diligent about abuse within their network.