Spam is the common term for electronic 'junk mail' – unwanted messages sent to a person's email account or mobile phone.
The content of spam messages varies. Some messages promote products or services, while others attempt to trick users into providing bank account or credit card details. Many spam messages contain offensive or fraudulent material, and some spread computer viruses.
Spam now makes up the majority of email traffic. Billions of unwanted spam messages clog up the internet, disrupt email delivery, reduce productivity and irritate users.