You seek to understand how Email Security.cloud determines whether a given message is spam or is a newsletter.
 

Please see the following excerpt from the online help for Email Security.cloud:

"Spam is defined as any unsolicited commercial email from unknown sources. The sender obtains the email address without the recipient's approval. Examples include phishing emails, advance-fee fraud scams (419 s.), and emails touting pharmaceuticals.

Newsletters are commercial emails. To receive a newsletter you need to subscribe to a mailing list. You may opt in unwittingly as part of a software installation, download registration, or membership registration. Examples of Web sites that opt users into email newsletters include Facebook, LinkedIn, and updates from company Web sites."

The original copy of this text is available publicly online at the following location:

https://techdocs.broadcom.com/us/en/symantec-security-software/email-security/email-security-cloud/1-0/faqs-about-newsletters-and-marketing-emails-v61419451-d2923e1901.html