What causes an IP/domain to get listed?

Blocklist listings typically result from specific triggering events that indicate spam or abuse. Understanding these causes helps prevent listings.

Spamtrap hits are a major cause. Sending to addresses that exist only to catch spammers proves poor list hygiene. Pristine traps are especially damaging because they could only be obtained through scraping or purchasing lists.

High complaint rates from recipients reporting your mail as spam can trigger listings. When enough users at an ISP complain, blocklist operators take notice.

Compromised systems sending spam from your IP get you listed regardless of your intentions. If malware or an attacker uses your server, the IP gets blocklisted.

Sending patterns that match spam behavior, such as massive volumes from new IPs or sending to large numbers of invalid addresses, trigger automated listings.

Blocklists catch those who behave like spammers. Whether intentional or not, the behavior triggers the consequence.