Blacklist
An email blacklist is a list of IP addresses or domains that inbox providers treat as unsafe. If you are on one, your emails are more likely to land in spam or get blocked before they arrive.
Also known as Blocklist, Denylist
An email blacklist is a list that email providers use when they decide which senders to trust. It collects IP addresses and domains that have caused problems in the past. When your details show up there, inboxes start to treat your messages with suspicion. Many of your emails will land in spam folders or never show up at all.
You usually get blacklisted when your email practices hurt recipient experience or trigger spam filters. This can come from high spam complaints, old or purchased lists, or missing authentication records. Being on a blacklist can cut your revenue and damage your sender reputation quickly. People who care about email performance track this closely and fix issues early.
If you find yourself on a blacklist, slow down and clean up before you send again. Remove cold or inactive contacts, confirm consent, and set up SPF, DKIM, and DMARC. Start sending to your most engaged subscribers first with small, targeted sends. Over time this helps rebuild trust with inbox providers and improves where your emails land.