Emails not being sent from Acquia dev desktop2, win7
Had the same problem and switched from XMail to Papercut recently:


  Papercut is a simplified SMTP server designed to only receive messages (not to send them on) with a GUI on top of it allowing you to see the messages it receives. It doesn't enforce any restrictions on addresses, it just takes the message and allows you see it.


So, turn off the XMail service and start Papercut. When a mail is sent in Drupal, Papercut acts as the (local) SMTP server and allows you to see the message.