Emails Going to Spam Because of a Blacklist? Here Is What to Do

Every time you send an email, the receiving mail server decides where it goes: the inbox, the spam folder, or nowhere at all. To make that decision quickly, many mail filters look up the sender and the links in the message on public spam blacklists (also called blocklists or DNSBLs). If something in your email matches a listing, the message gets a worse score and often ends up in junk.

The tricky part is that you usually get no warning. Your email program says the message was sent. The recipient simply never sees it, or finds it days later in the spam folder. Common signs are customers saying they never got an invoice, a sudden drop in replies, or bounce messages that mention a blocklist by name.

Being listed does not always mean you did something wrong. Lists can catch domains that were misused by someone else, domains with a compromised website, or domains that simply share a pattern with real spam. That is why the first job is to find out exactly what is listed and why.

There are two main kinds of spam blacklist, and they are fixed in different ways. Knowing which one you are dealing with saves a lot of wasted effort.

• Domain blacklists (sometimes called URI or RHS lists) list a domain name. Filters check the domain in your sender address and every domain that appears in links inside the email. Examples are the Spamhaus DBL and URIBL. If your own domain is listed, every email that mentions it can suffer, no matter which mail service you use.
• IP blacklists list the numeric address of a mail server. If you send through a provider such as Google Workspace, Microsoft 365 or an email marketing service, that server belongs to the provider, and they are the ones who monitor and fix its IP reputation. If you run your own mail server, the IP is yours to fix.
• Mailbox provider reputation is a third factor. Large providers like Gmail and Outlook keep their own internal score for your domain based on how recipients react to your mail. It is not a public list, and nobody can submit a removal request for it.

If a bounce message names an IP address rather than your domain, contact your email provider first. They control that server and can tell you whether the problem is on their side.

Before you blame a blacklist, rule out the more common causes. A clean blacklist check combined with poor inbox placement almost always points to one of these.

• Missing or broken authentication. SPF (a DNS record listing which servers may send for your domain), DKIM (a digital signature added to each message) and DMARC (a policy telling receivers what to do when the first two fail) help receivers trust that mail really comes from you. Large mailbox providers have become much stricter about these, especially for bulk senders.
• Content that looks like spam. Misleading subject lines, lots of images with little text, link shorteners, or attachments that receivers distrust can all lower your score.
• Complaints and low engagement. When many recipients mark your mail as spam, or never open it, providers learn to file it as junk.
• Old or purchased lists. Sending to addresses that no longer exist, or to people who never signed up, damages reputation quickly and can lead to blacklisting.
• A sudden jump in volume from a domain that normally sends very little.

The fastest way to get a clear answer is to run your domain through our free Email Blacklist Checker. It checks your domain against 20 spam blacklists, including Spamhaus DBL, URIBL and Abusix, and shows which ones list it. You do not need an account, and you can run up to 5 checks per hour.

Check the domain in your sender address first. Then check any other domains that appear in your emails, such as a separate shop domain, a tracking domain or a link shortener. A listing on any of them can affect delivery.

Also read any bounce messages you received. Many receiving servers include the name of the list that blocked the message, which tells you whether it was a domain list or an IP list. If you want to see whether your website is flagged by security vendors as well, use the Domain Blacklist Checker.

1. 1Run the free email blacklist check and write down every list that shows your domain, along with the date.
2. 2Confirm whether the listing is for your domain or for a mail server IP. Send IP listings to your email provider and ask them to investigate.
3. 3Look for the cause. Check your website for hacked pages or unfamiliar files, review recent campaigns and sign-up forms, and ask your team whether anyone has been sending unusual mail.
4. 4Fix the cause completely. Clean any compromised site, close abused sign-up forms, remove bad addresses from your lists and stop any campaign that triggered complaints.
5. 5Check SPF, DKIM and DMARC for your domain and correct anything missing, so the next messages you send are properly authenticated.
6. 6Read each list operator's own removal policy and submit a removal request through their official channel, one request per list.
7. 7Wait for the operator to respond, then run the check again to confirm the listing is gone. Send a few test emails to different providers to see where they land.

Spam list operators handle a lot of requests, and many of them are from real spammers. A clear, factual request stands out. Keep it short and include only what helps them verify that the problem is gone.

• The exact domain that is listed, and the list it appears on.
• A brief explanation of what caused the listing, if you found it (for example, a hacked contact form that was abused to send spam).
• What you changed to fix it, such as cleaning the site, updating software or tightening sign-up forms.
• How you send email today: which provider, and how people join your mailing list.
• A contact address that you actually check, so they can ask follow-up questions.

Do not send the same request over and over, and do not argue. Repeated or hostile messages tend to slow things down. Every operator sets its own process and timing.

Timing is set by each list operator, not by us. Some lists remove a domain within a day or so once the cause is fixed, some expire listings on their own after a period without new spam, and some take longer or ask for more information. Treat any timing as a rough estimate.

The most common mistake is requesting removal before the cause is fixed. If spam keeps pointing to your domain, it is likely to be listed again, and future requests may be treated with more caution. Other mistakes are switching to a brand new domain (which has no reputation and often performs worse), buying an email list to make up for lost replies, and ignoring an IP listing that only your provider can resolve.

We monitor your domain every day against the same 20 domain spam blacklists our free checker uses, plus 90+ security vendors such as Google Safe Browsing, Fortinet and Kaspersky. When a listing appears or clears, you get an email alert (instantly, or as an hourly or daily digest), and you can also receive webhooks.

When your domain is wrongly listed, our team reviews the listing, prepares the evidence, submits the removal request through each operator's official channel and follows up until they respond. You get a confirmation once the listing is removed.

To be clear about the limits: our delisting covers the 20 domain blacklists we monitor. We do not delist mail server IP addresses (your email provider handles those), and we cannot change the internal reputation that Gmail, Outlook or other mailbox providers keep. We also do not clean hacked websites or fix email authentication for you. If the listing is justified, we tell you what needs fixing and only submit a request once it is resolved; your developer, host or email provider does that work.

Pricing follows a no cure, no pay approach. A one-time case costs €39, paid when you open the case, and is refunded in full if the operator refuses to remove the listing. On subscription plans, a case credit is only used when removal is confirmed. If the same list re-lists your domain within 30 days of a confirmed removal and nothing changed on your side, we resubmit at no extra charge. This guarantee does not apply to justified listings, if you did not provide requested information, or if you withdrew the case.