what's the frequency of the letter "?" in:
q: select emails being sent i have recently been approached by an employee who claimed he was not getting all of his email sent from our server. therefore i opened up exchange system manager and navigated through message history. i found out that only 2 internal emails were receiving the automated messages despite the fact that 4 email addresses were listed in the to: field of the email. 
for example, the email lists recipient a,b,c,d's email in the to: field but only sends the message to recipient a and b. 
another piece worth noting is the emails are sent via the smtpclient class in visual basic, in .net 2.0
any ideas as to why the email is only being sent to certain clients email address's?

a: do you have the smtp logs enabled? it is quite possible that some of the mail's recipients have been refused right away, but your programmatic smtp client routine has not defined anything to handle this case and just swallowed the error responses. you would need to check the smtp logs for this particular message.

user
The text includes two "?"s in total.
assistant