Subject: Returned mail: see transcript for details

From: Mail Delivery Subsystem <[email-masked]>
Date: Mon, 20 Oct 2025 12:56:42 GMT

The original message was received at Mon, 20 Oct 2025 12:56:27 GMT
from mailcontrol@localhost

   ----- The following addresses had permanent fatal errors -----
[email-masked]
    (reason: 550 5.7.54 SMTP; Unable to relay recipient in non-accepted domain)

   ----- Transcript of session follows -----
... while talking to [62.181.221.14]:
>>> DATA
<<< 550 5.7.54 SMTP; Unable to relay recipient in non-accepted domain
550 5.1.1 [email-masked]... User unknown
<<< 503 5.5.2 Need rcpt command