Is Your Domain Blacklisted? How to Check and Get Delisted (2026 Guide)

Is Your Domain Blacklisted? How to Check and Get Delisted

Your emails were going out fine yesterday. Today clients say they never got your invoice, and some messages bounce back with errors like “550 5.7.1 rejected – listed at…”. One of the most common causes is that your domain or sending IP is on an email blacklist.

The good news is that blacklisting can almost always be fixed. Below we explain what a blacklist is, how to check yours in a few minutes, and what to do to get removed.

What is an email blacklist?

An email blacklist (also called a DNSBL or RBL) is a real-time database of IP addresses and domains reported for sending spam or showing suspicious behavior. Mail servers at Gmail, Outlook, corporate networks and ISPs check these lists before accepting a message. If you’re listed, your emails may be:

• rejected outright (hard bounce)
• delivered to the spam folder
• delayed or throttled

Some of the best-known lists are Spamhaus, Barracuda, SpamCop, and SORBS. Getting listed on a major one like Spamhaus can affect delivery to a large share of recipients.

Signs your domain or IP might be blacklisted

• Bounce messages that mention “blocked”, “listed”, “RBL” or a blacklist name
• A sudden drop in replies or open rates
• Clients saying your emails land in spam, even though nothing on your side changed
• Your hosting provider warns you about outgoing spam or limits your sending

How to run an email blacklist check

1. Find your sending IP. Open the full headers of an email you sent and look for the first Received: line from your mail server. If you use Google Workspace or Microsoft 365, your IP is shared, so focus on your domain instead.
2. Use a multi-list lookup tool. Free tools like MXToolbox Blacklist Check let you enter your domain or IP and check it against dozens of lists at once.
3. Check the domain separately. Domain-based lists (like Spamhaus DBL) flag domains that appear in spam content or links, even when your IP is clean.
4. Write down which lists flag you. Not every list carries the same weight. A listing on a small, rarely used list may have no real effect, while a Spamhaus or Barracuda listing usually needs immediate action.

Why domains and IPs get blacklisted

Blacklisting is rarely random. The most common causes we see are:

• A compromised mailbox. A stolen password lets someone send thousands of spam messages from your real account.
• A hacked website or contact form. Scripts on outdated WordPress plugins are often used to send spam from your server.
• A shared hosting IP. Another customer on the same server misbehaved, and the whole IP got listed.
• Missing authentication. Without SPF, DKIM and DMARC, your domain is easier to spoof and looks less trustworthy.
• Poor sending habits. Bulk emails to old or purchased lists cause high bounce rates and spam complaints.

How to get delisted, step by step

1. Fix the cause first. Requesting removal before the problem is solved usually means you get listed again quickly, and some lists make each new removal harder. Change compromised passwords, enable two-factor authentication, update or remove vulnerable plugins, and check outgoing mail logs for unusual volume.

2. Set up email authentication properly.

• SPF lists which servers may send mail for your domain.
• DKIM adds a cryptographic signature to every message.
• DMARC tells receiving servers what to do with mail that fails these checks, and sends you reports.

Since 2024, Gmail and Yahoo require authentication from bulk senders. Without it, deliverability suffers even if you’re not blacklisted.

3. Submit removal requests. Each blacklist has its own delisting page. Some remove you automatically after a set time once the spam stops. Others need a manual request explaining what you fixed. Be short, factual and honest.

4. If you’re on a shared IP, contact your hosting provider. You can’t delist a shared IP yourself, but your host can move you to a clean IP or deal with the listing.

5. Monitor afterwards. Run a blacklist check again after a few days, and keep reading your DMARC reports so you catch problems early.

How to stay off blacklists

• Use strong, unique passwords and 2FA on every mailbox
• Keep your website, CMS and plugins updated
• Only email people who opted in, and remove addresses that bounce
• Use a proper email service for newsletters instead of your regular mailbox
• Keep SPF, DKIM and DMARC in place, and move DMARC gradually toward p=quarantine or p=reject

Frequently asked questions

How long does blacklist removal take?
It depends on the list. Some remove you within hours of a request, others automatically after 24 hours to a few days once no new spam is seen.

Can I be blacklisted even if I never sent spam?
Yes. A shared IP, a spoofed domain or a hacked account can get you listed without anyone at your company doing anything wrong.

Will paying a blacklist get me removed faster?
Reputable lists like Spamhaus do not charge for delisting. Be careful with any list or service that asks for payment to remove you.

Need help fixing it?

Blacklist issues can mean lost invoices, missed leads and frustrated clients. At Send & Chill, we find what caused the listing, fix your DNS and authentication records, secure your mailbox and handle the delisting requests, so your emails reach the inbox again.

We reply within 24 hours!