Unfortunately, the it-nic got the "great" idea to start selling domains with accented characters to improve their revenues. :facepalm:Those domains may contains not only italian accented vowels, but even many others of other nations.So, even italian site with italian target have now to handle email addresses such as info@Iñtërnâtiônàlizætiøn.it. Trying to manage this problem using php, the only way I found is using the punycode translation, to that info@Iñtërnâtiônàlizætiøn.it becomes email@example.com I tested in the FROM field and it works (I don't have an email address with special chars to use for the tests). Anyway, this brings us to another problem: imagine this simple/frequent scenario1) Contact Web form. A guy inserts his data and sends it.2) The company receives the email and replies (if they don't know of punycode, will be quite scaring!).3) The guy of point 1, who inserted his email in plain utf-8, receives the reply at his address but with this strange, different email address, which is not what he typed in the web form, looking like phishing or spam. I also tried a different approch: mb_encode_mimeheader(): it seems ok visually in the email clients, but trying to reply, the address get into the encoded way... something like=?UTF-8?B?ScOxdMOrcm7DonRpw7Ruw6BsaXrDpnRpw7huQHJpa3NvZnQuaXQ=?=IMPRACTICAL, working or not! Does anyone know a better way to send emails with the host part with accented vowels?