Subject: Returned mail: see transcript for details
From: Mail Delivery Subsystem <[email-masked]>
To: <[email-masked]>
Date: Fri, 16 Aug 2024 16:36:26 -0400

The original message was received at Fri, 16 Aug 2024 16:36:25 -0400
from listserver-cap.dreamhost.com [69.163.136.34]

   ----- The following addresses had permanent fatal errors -----
<[email-masked]>
    (reason: 550 5.1.1 <[email-masked]>: Recipient address rejected: User unknown in virtual alias table)

   ----- Transcript of session follows -----
... while talking to [152.3.70.26]:
>>> DATA
<<< 550 5.1.1 <[email-masked]>: Recipient address rejected: User unknown in virtual alias table
550 5.1.1 <[email-masked]>... User unknown
<<< 554 5.5.1 Error: no valid recipients