[jeroenhd]

Messing with emoji taught me how absolutely atrocious unicode support among email servers is. Gmail supports it, but even modern versions of postfix require special compilation flags to enable SMTPUTF8.

While emoji aren't a use case you'll get many managers to care about, there are plenty of unicode characters that can. Email addresses using foreign script, for one, or even just characters like åäáà, not uncommon in European names, might convince people to consider enabling such features.

Sadly, the process of enabling support for such characters is much harder than it should and I've got to admit they my mail infrastructure also can't handle these types of email addresses. Modern MS Exchange servers seem to have finally implemented support, though, so perhaps we may see more support for it in the future!

[Avamander]

I think postfix's DB drivers were also still latin-1 only, if I'm not misremembering I had to mojibake what I wanted it to pick up.

Though UTF-8 is not the only thing atrocious with e-mail stacks, there's so much maintained-but-not-really non-standard software that a lot of people rely on.

To end on a positive note, e-mail hosts are starting to demand SPF to accept mail.