What is blacklist or blacklist?
First, "Spam" is defined as the mails that are sent to a large number of buyers, mostly advertisements that are sent to them unaware of the buyer.
That is, the databases in which IP addresses that are detected as spam are stored are called blacklist. Blacklisters are held in companies' own databases as well as by all globally recognized organizations.
The greatest of them,
1- Spamhaus 2- Spamcop 3- UCEPROTECT 4- TrendMicro 5- Sorbs 6- Barracuda
The Blacklist's processing algorithm is as follows. However, the "Rule Phase" tab is different for each company. If the mailed IP is received by the spam organizations as a blacklist;
a- The incoming mail is rejected and the sender error message is sent.
b- Drops into the Mailbox without any processing.
c- The incoming mail is marked and sent to the Mailbox according to the rules established by the receiving company.