아웃룩으로 메일을 보내면 거의 잘 가는데, 몇몇이 안가서 따로 개인메일로 보냅니다
문제를 보내드리는데, 확인이 가능할까요?
예전에 아웃룩에서는 한메일이 잘 안간다고 해서 한메일(다음포함)은 안보네는데, 이런 일반적인것
까지 안되면 불편해서요

Returned mail: see transcript for details
Mail Delivery Subsystem [MAILER-DAEMON at
bora.byus.net]

The original message was received at Fri, 14 Nov 2014 09:39:53 +0900 from [209.85.192.169]

   ----- The following addresses had permanent fatal errors ----- <hsbi at hs.ac.kr>
    (reason: 550 5.1.1 <hsbi at hs.ac.kr>: Recipient
address rejected: User unknown in virtual 
mailbox table)

   ----- Transcript of session follows ----- ... while talking to [203.252.23.10]:
>>> DATA
<<< 550 5.1.1 <hsbi at hs.ac.kr>: Recipient
address rejected: User unknown in virtual mailbox 
table
550 5.1.1 <hsbi at hs.ac.kr>... User