Email spam
An email is defined as spam when it is unsolicited and is
sent as part of a large collection of messages, meaning in a bulk.
It is also known as Unsolicited Bulk Email ("UBE").
The content of the email is not relevant for categorizing it as spam.
It could be porn, a begging letter, a scam or an advertisement and not be spam.
The only criteria is that the message is sent unsolicited and in a bulk.
Sending email spam is forbidden by all ISPs
(=Internet Service Providers).