There is already MailMessage::encodeWord, but the corresponding decode is missing. This makes it difficult to use this library efficiently and leads to many wrong implementations, since this subject is not trivial to implement.

See http://stackoverflow.com/questions/41422934/c-decode-e-mails-subject