Is My Email Blacklisted? How to Check and Get Delisted

A blacklist listing can silently kill your deliverability — your emails appear to send normally but are rejected or filtered at scale. Here is how to check every major list and what to do if you are listed.

What Is an Email Blacklist?

An email blacklist (also called a blocklist or DNSBL — DNS-based block list) is a real-time database of IP addresses and domains associated with spam or malicious sending. Mail servers query these lists during the SMTP connection process and reject or filter mail from listed sources.

There are hundreds of blacklists, but a handful control the vast majority of deliverability outcomes. Being listed on Spamhaus alone can block delivery to 40%+ of global inboxes.

Major Blacklists to Monitor

How to Check If You Are Blacklisted

1. 1

   MXToolbox Blacklist Check

   Go to mxtoolbox.com/blacklists.aspx and enter your sending IP or domain. It queries 100+ lists simultaneously and shows which ones you appear on.

2. 2

   Spamhaus Lookup

   Check directly at spamhaus.org/lookup — the most authoritative source for SBL, DBL, and ZEN listings.

3. 3

   Barracuda Lookup

   Use barracudacentral.org/lookups to check your IP against the Barracuda Reputation Block List.

4. 4

   MultiRBL

   multirbl.valli.org checks your IP against 200+ lists with response codes — useful for identifying less-common lists.

5. 5

   Google Postmaster Tools

   Not a blacklist check per se, but Low or Bad domain reputation in Postmaster Tools often coincides with blacklist issues affecting Gmail delivery.

How to Get Delisted

1. 1

   Identify why you were listed

   Blacklists publish listing reasons. Common causes: spam trap hits, high complaint rates, sending from a compromised server, or using a purchased list.

2. 2

   Stop the problematic sending immediately

   Pause campaigns while investigating. Continuing to send while listed makes delisting harder and re-listing faster.

3. 3

   Scrub your list with FareOf

   Run a full verification pass to identify and remove invalid addresses, spam traps, and high-risk contacts that caused the listing.

4. 4

   Fix authentication

   Confirm SPF, DKIM, and DMARC all pass. Authentication failures are a listing factor for many blocklists.

5. 5

   Submit a delisting request

   Each list has its own process. Spamhaus requires a removal request at spamhaus.org/removal. Barracuda at barracudacentral.org/rbl/removal. Include the corrective actions you have taken.

6. 6

   Monitor for re-listing

   Set up automated blacklist monitoring (MXToolbox offers this as a subscription). Check daily for the first two weeks after delisting.

Prevention Checklist