There is actually no very strict definition of spam. Generally speaking, any email that is forcibly sent to a user's mailbox without the user's permission can be considered spam, including the recipient. Emails sent from blacklisted email addresses.
#Spam does not yet have a very strict definition. Generally speaking, any email that is forcefully sent to a user's mailbox without their permission is spam.
Spam refers to unsolicited emails. Emails that meet the following characteristics belong to the category of spam:
1. From an address where the recipient has never sent an email. The first email sent, as well as other emails subsequently sent to the recipient from the same address if the email has not been customized as a normal email by the recipient;
2. From rejected receipts Other emails sent to the recipient from the email address;
3. Emails from the email address blacklisted by the recipient;
4. The content contains content that can be anti-spam Emails with key fields that are installed or can be defined by email filters and classified as spam;
5. Emails with false or invalid email headers, emails with false or invalid domain names, and emails that have been technically processed Emails that do not display any source information. Emails with deceptive address information;
6. Emails used, relayed or sent through third-party Internet equipment without consent;
7. Subject lines or content contain errors , misleading or false information.
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