SMTP error when sending to disabled mailbox on Sun One mail server

One of the truly most obscure errors I have came across recently is in an Exchange 2003 deployment for the U.S. Army. The Army sends most of their mail through a centralized system called AKO; this allows all Army active duty personnel and civilians to have a single address regardless of where they are currently serving.

A user (a user with a couple of stars on his lapel) reported this NDR): (I have removed the real SMTP addresses for privacy sake).

Final-Recipient: rfc822;xyzzy.zyzz@us.army.mil
Action: failed
Status: 2.1.5
Diagnostic-Code: smtp;250 2.1.5 xyzzy.zyzz@us.army.mil and options OK.

Final-Recipient: rfc822;abc.asdfas@us.army.mil
Action: failed
Status: 2.1.5
Diagnostic-Code: smtp;250 2.1.5 abc.asdfas@us.army.mil and options OK.

Final-Recipient: rfc822;jsksfa.dlkadf@us.army.mil
Action: failed
Status: 2.1.5
Diagnostic-Code: smtp;250 2.1.5 jsksfa.dlkadf@us.army.mil and options OK.

Upon further investigation this in the SMTP protocol log on the Exchange 2003 bridgehead server:

04:44:54 143.69.243.33 RCPT - TO:+NOTIFY=FAILURE,DELAY
004:44:54 143.69.243.33 RCPT - TO:@us.army.mil>+NOTIFY=FAILURE,DELAY
004:44:54 143.69.243.33 RCPT - TO:@us.army.mil>+NOTIFY=FAILURE,DELAY
004:44:54 143.69.243.33 RCPT - TO:+NOTIFY=FAILURE,DELAY
004:44:54 143.69.243.33 RCPT - TO:@us.army.mil>+NOTIFY=FAILURE,DELAY
004:44:54 143.69.243.33 RCPT - TO:@us.army.mil>+NOTIFY=FAILURE,DELAY
004:44:54 143.69.243.33 RCPT - TO:@us.army.mil>+NOTIFY=FAILURE,DELAY
004:44:54 143.69.243.33 - - mailto:250+2.1.5+xyzzyy.zxcvas@us.army.mil+and+options+OK.
004:44:54 143.69.243.33 - - mailto:250+2.1.5+xyzzyy.zxcvas@us.army.mil+and+options+OK.
004:44:54 143.69.243.33 - - mailto:250+2.1.5+xyzzyy.zxcvas@us.army.mil+and+options+OK.
004:44:54 143.69.243.33 - - mailto:250+2.1.5+xyzzyy.zxcvas@us.army.mil+and+options+OK.
004:44:54 143.69.243.33 - - 452+4.2.1+Mailbox+temporarily+disabled:+xyzzyy.zxcvas@us.army.mil
004:44:54 143.69.243.33 - - mailto:250+2.1.5+xyzzyy.zxcvas@us.army.mil+and+options+OK.
004:44:54 143.69.243.33 - - mailto:250+2.1.5+xyzzyy.zxcvas@us.army.mil+and+options+OK.
004:44:54 143.69.243.33 - - 250+2.1.5+xyzzyy.zxcvas@us.army.mil+and+options+OK.


Basically, the Sun One mail server spit back a 452 4.2.1 Mailbox temporarily disabled message for only ONE mailbox. The rest of the messages were all delivered normally, but the VIP received an NDR for everyone AFTER the undeliverable recipient.

Apparently, similar problems exist in this situation for Exchange 5.5 and 2000. Microsoft has a hotfix you can now get from PSS that addresses this issue, but it was a pain to track down.