History and Evolution of Electronic Mail(and a bit of a tutorial)
About Internet History – A Disclaimer
More Warnings
Before the Beginning: Messages to the Computer Operator
The CTSS Insight
Parallel and Slightly Later Developments
From the Beginning
Then the ARPANET Happened
Alternative Mail Systems
A World of Gateways
SMTP as Common Denominator
It Just Works(and the robustness principle)
Why Internationalize?
Going Multilingual and Multimedia
The Internationalization Tradeoff and People
Rare and Endangered Languages and Scripts
Requirements for internationalized message content
ESMTP and MIME
The Internationalization Tradeoff and Computer Networks
Be Careful What You Try to Internationalize
Internationalizing Domain Names
Are IDNs Necessary?
Beyond content to addresses
Gateways and “No one tampers”
Messages with New Addresses to Old Systems
Mail Transport
Why no “downgrading”?
Why no “downgrading”?
Email Extended for Non-ASCII Addresses – Characteristics
Where the Issues Lie
I Did Not Talk About MUAs
As the Extensions Deploy…
Email Probably Has A Future

Email Extended for Non-ASCII Addresses – Characteristics

local-part@domain – entirely Unicode UTF-8
Requires non-ASCII Unicode support in header field data
Addresses in envelope
Supported through SMTP extension
No fallback or translation/ coding in transit.
System accepting the extensions must be prepared for any Unicode-supported script
New addresses + older systems: No communication