Question is what is Blacklisting?
When a domain or ip start sending spoofing mails in bulk or are regular in malicious activities then that ip or domain gets block on several places so that they will not be able to send mails.
There are several tools online which filters the ip and domain and put them in a block list and this is called blacklisting.
When malicious activities are observed on a ip then that ip get blacklisted, protecting the receivers from getting a piece of spam.
When malicious activities are observed from a domain then that domain get blacklisted.
These blacklisted ip and domain can also be removed by using tools that are available online. However, removal of ip can take particular time period starting from 30 minutes to 30 days or more, depending on the spam content that particular ip or domain was doing.
Reasons for Blacklisting:
- Spam trap mail id’s
- Spam Keywords
- Email Content