cortig

The Workflow sure works great for me, but I'm trying to understand your approach (and create other workflows on the same idea for other e-mail clients).

Why use a script at all? Can the same thing be done with a filter?

You can limit the scope to ~/Library/Mail/V2 and use the kMDItemAuthorEmailAddresses, kMDItemAuthors and kMDItemSubject metadata fields.

What's wrong with that approach?

I'm unsure how it all works, because I've ran into a few things I couldn't figure out when I tried (eg: using kMDItemContentType didn't seem to make any difference at all, that's why I eventually had to resort to limiting the scope).

I don't know if it is doable, but could the localization be provided as some sort of a plugin containing the corresponing .lproj?

Then the plug-in would have to be updated by whoever provided it, without slowing down the releases. You also wouldn't take the blame for any lack of quality in the localization work…

Just a thought :-)