The Dutch internationalizations leave a few things to be desired:
When closing an email without sending it, I get a dialog box asking me if I want to save the email as a concept. The Options are:
When answering an email and quoting a passage, Airmail prefixes this with:
"Op 5 januari 2015 bij 12:21:48, Elise van Looij (firstname.lastname@example.org) schreef: "
That's not good syntax in Dutch: in a sentence starting with a preposition, the subject-verb order gets reversed:
"Op <datum> schreef Elise van Looij :"
"Elise van Looij schreef op <datum>"
The most left "Annuleren" option could/should be "Verwijderen" (Delete)