A commercial electronic message (CEM) is a communication soliciting business, funding or support for something that is sent through any electronic channel, including email, social media, voicemail, text and instant messages.
CEM is not necessarily spam, more formally known as unsolicited bulk email (UBE). However, any commercial messages sent without either implied or express consent are typically considered spam and, depending on where you and the recipients live, may also be illegal.
The most common type of spam is unsolicited commercial email (UCE): bulk email that is trying to get the recipient to buy some product or service. In many countries, CEM falls into this category if you have not provided a means of opting out. More stringent regulations, such as Canadian anti-spam legislation (CASL), require senders to obtain express consent from recipients before sending their messages.