User tells me that email recipient tells him that messages he sent were not received. Recipient is at @yahoo.com. I look in user's sent folder and they are there, looking good. Message #1 was sent on 8/3/2007 and message #2 was sent on 8/6/2007.
Neither message is currently showing up in the SMTP queue, in fact no messages are showing up in the queue; outgoing messages usually leave that queue very quickly.
I look them up in the exchange system manager message tracking center and get these results (just reproducing the last line here):
1) message #1: Message transferred to mta204.mail.mud.yahoo.com through SMTP
2) message #2: SMTP: started Outbound Transfer of Message
It looks to me like message #1 was delivered successfully, but I don't know for sure that the recipient got it.
It looks to me like message #2 was not, but for this message I am puzzled why some additional error message did not show up somewhere.
Questions: 1) is my assumption about message #1 correct? (that the user would have received it)
2) is my assumption about message #2 correct? (that the user did not recieve it)
3) why did message #2 not generate any additional error or result in a non-delivery or still show up in the outbound queue.
Caveat to question #3: The user will not guarantee that he didn't delete some non-delivery messages, although he would have had to delete two of them (one for the delay and one for the failure); he doesn't remember and unfortunately cleaned out his deleted folder before reporting this problem.