MetaMask includes a self-custodial (also commonly referred to as non-custodial) cryptocurrency and token wallet. It gives you complete control of your access keys and therefore your assets.
'Self-custodial' refers to the fact that it's you ('self') who holds your wallet's private key(s). A self-custodial wallet eliminates the third party between you and your crypto-assets, which is more suitable for some people.
MetaMask doesn't store any data about the wallet. Everything you see is in your browser or your mobile app at a local level. There are no email addresses associated with accounts. There is only a Secret Recovery Phrase (seed phrase) that is given once and cannot be changed or reset. Also, if you have imported other accounts using their private keys, their Secret Recovery Phrases should also never be shared. Please store your Secret Recovery Phrase and private keys offline and back them up.
For more detail on this topic, see our blog post here.
MetaMask and email addresses
You open and use your MetaMask wallet without ever inputting your email. This privacy is part of MetaMask's identity. However, we may have your email address if you have used our Support services, as we it need to track your issue and follow up with you. This doesn't apply for conversations that you begin using the 'Start a Conversation' button. We may also have your email if you've signed up for the MetaMask newsletter.
You should be highly sceptical of any emails you receive claiming to be from us. If you have never had help from Support, the email will be a phishing scam; even if it is from us, we will never ask for your Secret Recovery Phrase (seed phrase).
Because of MetaMask's self-custodial design, we cannot access your wallet from our side. You are the only person who can access it directly from the Extension or Mobile app.
Learn more about your Secret Recovery Phrase and how to keep your account safe here.