A spam email is an email sent without the person signing up or giving out there email address to the person sending the email.
A cold email could also be spam if the person receiving the cold email did not signup or give you there email address.
If they did signup for something on your website and willingly gave you there email then it's not considered spam to send the person an email address if they agreed to receive emails from you even if you're advertising something you're selling or anything else.