Sending email from excel

I have a code that will send my invoice from excel to outlook and send as a PDF email. The code works perfect except sometimes the email is stuck in outbox,could be number of reasons such as poor internet connection. My question is has anyone found a way to have a message pop up saying email sending then close the message after mail sent? Is there a way to put the number of outbox emails in a cell in excel. IF I could get the number in a cell might find a way for message box.Any suggestions on this?
Thanks