I see nothing wrong to encode ordinary ASCII headers with ?koir-8?
style. If you want to check against headers containing Cyrillic letters,
While that's in theory true, it's in practice rare.
Still maybe they know that they converse with no-one that ever uses any
Russian encoding system with their email client, so blocking all koir-8
headers is still a reasonable action.
if header :contains "subject" "е" { ... }
shall do the work, where "e" is Unicode 0435.
I presume "e" (unicode 0435) is a common character in Russian text. Still
there's no guarantee that a Russian header will contain an "e" (unicode
0435) in it.
It doesn't get past the point that there is still no way to look at the raw
undecoded header even if you wanted to for some other reason.
Am I missing something? Was that intentional in the spec?
Rob