Gmail Spam box is where all spam messages are automatically moved into and cleared after some time. Spam is also known as junk emails. If you don't know what a spam message is, it's undesired electronic content that is generated for commercial rather than personal purposes. Spam messages are usually sent in bulk, which means they're generalized and not personalized. This makes it easy to detect, even before you read the content halfway. Gmail uses the latest technologies to filter spam messages away from your inbox. They will be automatically moved to a separate folder and will be deleted after 30 days.