Many times in the applications I program there is a requirement of sending an automatic email. I prefer to create a new GMAIL account to send the emails. In some organization smtp.gmail.com is blocked. Here is a simple test to check if it is going to work:
Telnet smtp.gmail.com 587
If you get the message : "Connecting To smtp.gmail.com...Could not open connection to the host, on port 587: Connect failed"
Then its blocked.
If you get something like : "220 mx.google.com ...."
It is going to work.