You are welcome.
That is a news to me since I created Sandbox 2 days ago and has Email Accounts still active.
usually what I do right after creating Sandbox is
1) Make sure all Job Queue are on hold.
2) Delete all emails from Email Account (if disabling that service prevent emails is even better, I will test next time).
3) Go to SO (or somewhere else) to test and see if I can send email.
4) We have one email (such as test@domain.com) for this email we have a rule that stop this email to send email outside of our org (in exchange email setup).
5) I set that email as a default email for everything in Sandbox (SMTP setup). This way I still can test and if by mistake anything run it will be through that email that cannot go outside of org.
