Did you try IDN / Punnycode converter? Try abuse@xn--zrich-kva.email ? ________________________________ From: anti-abuse-wg <anti-abuse-wg-bounces@ripe.net> on behalf of Thomas Hungenberg <th@cert-bund.de> Sent: Tuesday, November 19, 2019 2:27:13 PM To: anti-abuse-wg@ripe.net <anti-abuse-wg@ripe.net> Subject: [anti-abuse-wg] Non-ASCII characters in abuse-mailbox addresses Hi, some abuse contacts registered with RIPE use non-ascii characters with the abuse-mailbox addresses, e.g. % Abuse contact for '195.78.76.0 - 195.78.77.255' is 'abuse@zürich.email' However, the corresponding MTA does not support SMTPUTF8: 7B579403C6: to=<abuse@zürich.email>, relay=mail.xn--zrich-kva.email[109.95.241.50]:25, delay=0.33, delays=0.01/0/0.32/0, dsn=5.6.7, status=bounced (SMTPUTF8 is required, but was not offered by host mail.xn--zrich-kva.email[109.95.241.50]) (In this particular case, sending email to the IDNA representation of the email address <abuse@xn--zrich-kva.email> works.) In our experience, using umlauts and other non-ascii characters in (the host part of) email addresses still cause a lot of problems in general. Even if the recipient's MX supports SMTPUTF8 correctly, MTAs on the transport way may fail to handle SMTPUTF8 messages. To prevent such problems and make sure all abuse mailboxes can be addressed, I wonder if the values of abuse-mailbox attributes should be restricted to ASCII characters only. What do you think? - Thomas