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제목 : [NDR] Delivery Failure Notice : 

첨부화일 내용 : delivery-status.txt (0.31K) 
Your message can't be delivered to the following recipients: 

Report-MTA: DNS; ruby2.snu.ac.kr 
Remote-MTA: 
Recipient: RFC822; ****@**** 
Action: failed 
Status: 5.2.1 
Diagnostic-code: 550 Classified as SPAM, so returned 

This report relates to a message you sent with the following header fileds: 


메일 내용 
Your message cannot be delivered to the following recipients: 

Recipient :****@**** 
Reason:550 Classified as SPAM, so returned