http://mynymecyaiv7t55qiggp76rzqz35si5g7nzdh3yci4wiqbmlwqg7xeyd.onion/email-hosting
With that module you can create, import and manage your keys. You can also sign, encrypt and decrypt emails and even files! How do you handle spam? We run a spamfilter, every user is able to create own rules, blacklists and whitelists.