Gmail errors "Please turn on SMTP Authentication" and "Recipient not found"

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Santeri
Posts: 128
Joined: 2017-7-5 09:58

Gmail errors "Please turn on SMTP Authentication" and "Recipient not found"

Unread post by Santeri » 2019-12-11 09:07

I made a web app using internationalized domain name (IDN). The domain name is lisäämyyntiä.com which is in punycode format https://www.xn--lismyynti-x2aag.com/. When I send email to the IDN, Gmail is giving me error messages claiming that the receiving email server is misconfigured.
Message not delivered

Your message couldn't be delivered to test@lisäämyyntiä.com because the remote server is misconfigured. See the technical details below for more information.
Same errors happen with or without punycode. Here are the specific, likely bogus Gmail error messages:
550 5.1.1 <test@xn--lismyynti-x2aag.com> Recipient not found. <http://x.co/irbounce>
550 Please turn on SMTP Authentication in your mail client. mail-ot1-f47.google.com [209.85.210.47]:46638 is not permitted to relay through this server without authentication.
IDNs are messing up Gmail. Other email clients don't give errors when sending emails to punycoded IDN:s. Also the email server works fine and relays, bounces and accepts email from Gmail to all non-IDN-domain without any problems.
Image Image I reported this issue to Gmail, but as they don't have a proper error reporting tool, I don't really expect them to do anything to fix this.