The company also changed its terms of service to remove all ads from the site and add more restrictions.
Firefox will not allow advertisers to send you emails that are spammy, it said.
Mozilla said that “we can’t control what the content of emails are or how they’re shared, but we can prevent malicious content from appearing in email or other public places.”
Mozilla added that it would be “taking action” against those who violate its terms, including “advertisers that knowingly share information about users’ browsing habits.”
Mozilla said it would also be “looking into the possibility of taking action against those individuals who continue to publish ads in violation of our policies.”
The update came a week before Firefox updated its Firefox OS to include a feature called the “Ad Blocker” that can block ads from being served.
Firefox OS users who have previously used Firefox can still disable the feature by installing the update.
Mozilla also made changes to Firefox’s ad-blocker, adding a new feature that makes it easier to disable ads from ads you’re using.
It also added the ability to block ad blocking software, like AdBlock Plus.
“When you use a third-party ad blocker, you can also block specific types of ads that Mozilla believes are spam or potentially harmful,” the update said.
Firefox is also adding a “Privacy Shield” feature that gives the company access to a database of user data it collects when you visit its sites.
“If you do decide to continue using our products, you should always opt-out of all third-parties tracking your online behavior,” Mozilla said.