The Unwanted Texts and the Telephone Consumer Protection Act (TCPA), bans many text messages sent to a mobile phone using an autodialer. These texts are banned unless (1) you previously gave consent to receive the message or (2) the message is sent for emergency purposes. This ban applies even if you have not placed your mobile phone number on the national Do-Not-Call list of numbers telemarketers must not call.
The CAN-SPAM Act supplements the consumer protections provided by the TCPA. The CAN-SPAM law bans unwanted email messages sent to your mobile phone if they are "commercial messages."(Email messages can sometimes appear as texts on your mobile phone, depending on how they're addressed.)
According to the Federal Communications Commission website "The CAN-SPAM Act defines commercial messages as those that primarily advertise or promote a commercial product or service. The FCC' ban does not cover "transactional or relationship"messages -- that is, notices to facilitate a transaction you have already agreed to -- for example, messages that provide information about your existing account or warranty information about a product you've purchased. The FCC' ban also does not cover non-commercial messages, such as messages about candidates for public office, or email messages that you have forwarded from your computer to your wireless device (but read below about the FTC' rules that may restrict such messages).
Federal rules require the following for commercial email sent to your mobile phone:
Identification---The email must be clearly identified as a solicitation or advertisement for products or services;
Opt-Out---The email must provide easily-accessible, legitimate, and free ways for you to reject future messages from that sender;
Return Address--- The email must contain legitimate return email addresses, as well as the sender' postal address."