Users with non-ASCII usernames will send malformated e-mails

[paravoid]

WiND is not encoding (using RFC 2047/encode_rfc2047 function) the recipient of an email address -- IOW, (part of) the $to argument of sendmail(). This will work with users with ASCII (7-bit) usernames but it will fail when using a non-ASCII (e.g. UTF-8) username. This isn't trivial to fix because _only_ the realname should be encoded and not the 'Realname <user@…>' (the actual contents of $to).

Therefore, the arguments of sendmail() should be changed to separate $to like $from ($to_name/$to_email).