IPv4 addresses are limited, so providers reuse them. If a past owner sent spam, attacked other servers, or ran an open proxy, the address was added to blocklists. When the IP moves to you, that record often moves with it. This is called a dirty IP.

A dirty IP can:
→ send your email to spam
→ get your API calls and webhooks blocked
→ stop visitors on some corporate networks from reaching your site

The good news: you can check an IP in two minutes, and you can fix most cases. The best time to check is right after you create a server, before you deploy anything.

In the full post: how IPs get dirty, how to check yours, and five steps to take if you have one.

Read it here: https://www.doprax.com/blog/what-is-a-dirty-ip