EAI is a set of RFCs to enable unicode email addresses. jøran@example.com and even jøran@blåbærsyltetøy.no are syntactically valid email addresses. There are RFCs to extend the email message syntax, to transmit these messages via SMTP, access them via POP and IMAP, and to provide read access by unextended IMAP/POP clients.
I wrote a set of test messages for EAI this morning and put them on github. Feel free to send me extensions and corrections.