Glossary definition of Opt out

Opt-out is the term used to describe the situation when a recipient has been given the opportunity to block communications or marketing information that they have been offered over the Internet or mobile services.

Typically, customers may find themselves receiving unwanted mail due to their details appearing on a mailing list, but good practice dictates that such e-mails should contain a message that they can 'opt-out' from receiving further mail by removing themselves from the mailing list.