I’ve recently taken to documenting and simplifying the steps for using Mixmaster with Nymservers – a setup that allows sending and receiving email pseudonymously without reliance on a service provider. Mixmaster comes with Whonix. Feel free to give it a try and post feedback in the forums.
Years later, the Mixmaster remailer network is still around even if its not what it used to be. The focus has since shifted from Mixmaster to Tor because it can anonymize a variety of communications and not just email, also it can do so efficiently, meeting high performance demands. However, as long as the legacy SMTP mail protocol hangs around, Mixmaster remains a very powerful and relevant option.
Sending pseudonymous mail promises to be simpler still thanks to Nymphemeral, a nym management Swiss army-knife GUI, written in Python. Its built around next-generation Nymservers that support Perfect Forward Secrecy.