>> Then a bounced message from the server comes in, saying the server cannot send this message to the recipient(s), though the listed email address is correct.
>
>Is it saying anything about WHY "the server cannot send this message to the recipient(s)"? Could you post here the exact message?

Nothing specific. It says the following

Undeliverable:MyMessageSubject
Your message did not reach some or all of the intended recipients.
emailaddress1
None of your e-mail accounts could send to this recipient.
...

But if I retype the emailAddresses in the outlook after the outlook is brought up, it sents. I guess it is related to the server. But I don't know how can use this mapi object to find out this.