When sending email , the following msg appears: You have chosen to use your gmail account to send emails. Please make sure that your authentication information is correct, otherwise email messages will not be sent. Test gmail connection. Can this disappear after the first time (or after the user has clicked to test the gmail connection)?
There is a user setting called "Experience Level" (see Setup > Personal Setup > Settings). Changing this from Novice to Experienced will hide all of the yellow help boxes like this. Eventually we may provide ability to hide them on an individual basis.
Hope this helps,
Matt