If is was not for the numerous Spam and promotional emails you receive everyday, you inbox would have looked much better and organised. Nobody knows from where spam mails originate but for promotional mails you must to have signed up for an newsletter somewhere.
Unlike spam emails, most promotional mails can be stopped by unsubscribing from them and if someone is legally sending an promotional mail, it is mandatory for him to provide an option for unsubscribing from future emails in case the recipient is not interested in receiving further emails.
Most of the time, marketeers usually provide an option to unsubscribe at the bottom of the promotional emails. Clicking on it will take you to another page where you can unsubscribe from any further promotional emails permanently.
Fortunately Google’s latest update for Gmail brings an useful feature that now lists the unsubscribe button at the top of every email. If an promotional email contains an option to unsubscribe from it, google will now make the unsubscribe button appear at the top of every email. Just click on it and you can easily unsubscribe from any further promotional emails.