If your emails are consistently landing in spam, or worse, bouncing outright, your domain or sending IP may be blacklisted. This guide covers how to check whether you're blacklisted, why it happens, and the exact steps to get removed and prevent it from happening again.
The first step is confirming the problem. Use our Blacklist Checker to run a check against your domain and your outbound mail server's IP address. It checks against major blacklists simultaneously, including Spamhaus, Barracuda, SORBS, and SpamCop, the ones that actually matter to major email providers.
Also check Google Postmaster Tools (postmaster.google.com) if you send a meaningful volume of email to Gmail addresses. It shows your domain reputation, IP reputation, spam rate, and authentication pass rates. If your spam rate is above 0.1%, Google will start throttling or filtering your mail. Above 0.3% triggers more aggressive action.
For Microsoft/Outlook recipients, check Sender Information for Outlook.com at sendersupport.olc.protection.outlook.com. Microsoft maintains their own blocklist separate from third-party services.
Sending to old or purchased lists. This is the most common cause for small businesses. If you import a contact list that contains invalid or spam-trap addresses, your bounce rate and spam complaint rate spike immediately. Never buy email lists. Even a list you collected years ago needs to be re-validated before sending a campaign.
Missing or broken SPF/DKIM/DMARC records. Email without proper authentication is more likely to be flagged as suspicious. Spamhaus in particular looks at whether your domain is properly configured. A domain without DMARC is a domain that can be spoofed, which affects its reputation even if you haven't done anything wrong.
Shared IP reputation. If you're on shared hosting and another account on the same mail server gets reported for spam, your sending IP gets flagged too. This is one of the strongest arguments for using a dedicated email host with its own IP pools.
High complaint rates. If recipients mark your emails as spam at a rate above 0.1%, major providers take action. This happens when your unsubscribe links are broken, when you send to people who didn't opt in, or when your email content is misleading.
Each blacklist has its own removal process. Spamhaus is the most important, it feeds many other lists. Check your status at check.spamhaus.org. If you're listed, they provide a self-service removal form for some list types (SBL, PBL) but require evidence of the root cause being resolved before removing others (XBL, DBL).
Barracuda offers self-service removal at barracudacentral.org/lookups after a 30-day clean sending period. SORBS removal requires emailing their abuse team with your IP and an explanation. SpamCop listings expire automatically after 24 hours if no new reports come in, though fixing the root cause first is essential.
Before requesting removal from any list, fix the underlying problem. If you submit a removal request and continue the behaviour that caused the listing, you'll be re-listed within days, and repeat listings are harder to remove.
Once you've identified the cause, ensure your DNS records are correct. Your SPF record should reference only the servers that legitimately send your mail. A common mistake is having multiple SPF records (only one is allowed) or including too many include: statements which exceed the 10 DNS lookup limit.
Verify your DKIM signature is correctly published using our DKIM Checker, and confirm your SPF record is valid with the SPF Checker. For DMARC, start with p=none and use a reporting address to monitor results for 2 to 4 weeks before tightening to p=quarantine.
A dirty list is the fastest route back onto a blacklist. Use a list validation tool before sending any campaign: NeverBounce, ZeroBounce, or Bouncer are the leading options. They check addresses against known spam traps, identify invalid formats, and test SMTP-level delivery without sending actual mail. Expect to remove 5–20% of a list that hasn't been cleaned in over a year.
Also set up proper bounce handling in your email system. Hard bounces (permanent failures) should be automatically unsubscribed after the first occurrence. Soft bounces (temporary failures) should be retried no more than 3 times before being flagged for review.
The fundamentals of ongoing deliverability are simple: only send to people who opted in, include a working one-click unsubscribe link, keep your complaint rate below 0.1%, authenticate your domain with SPF/DKIM/DMARC, and monitor your sending reputation monthly using our Blacklist Checker and Google Postmaster Tools.
If you send marketing emails, use a dedicated sending service (Mailchimp, Postmark, SendGrid, Amazon SES) rather than your business email server. These services manage IP reputation at scale, handle bounces and complaints automatically, and have established relationships with the major providers. Reserve your business email server for transactional and 1:1 communication.
HostBible email hosting uses clean IP pools, enforced SPF/DKIM support, and built-in spam filtering to keep your outbound reputation intact from day one.
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