Re: [anti-abuse-wg] Non-ASCII characters in abuse-mailbox addresses

On 19.11.19 15:21, Michele Neylon - Blacknight wrote:

If your email client or server can’t handle UTF-8 then doing the punycode conversion is unlikely to help

Based on our experience, it does help. If messages bounce because the recipient's MTA does not support SMTPUTF8, sending the message to the IDNA representation of the recipient address usually works. But I have also seen cases where the recipient's MTA supported SMTPUTF8 correcty but some MTAs or services like spam filters on the transport way did not and thus screwed up delivery of the message. - Thomas CERT-Bund Incident Response & Malware Analysis Team