Unwanted mail, also known as 'junk mail' or 'spam, ' is a term used to describe unsolicited emails or physical mail sent to an individual or organization. The two crossword solutions for this term are BILL and SPAM. BILL is an acronym for 'Bulk Internet Linking Language, ' which is a type of computer language used to send out large volumes of emails. SPAM is an acronym for 'Send-Packed Advertising Messages, ' which is a type of email marketing used to send out promotional messages.