Using The qmail-klepto Patch
Stop your development email from leaking to the world with the qmail-klepto patch!
Why
Almost all web applications, from a simple contact form to a massively complex CRM, send email notifications to their users. However, it is absolutely crucial that emails generated on your development, staging, and testing servers do not make it out to your production users in the real world. At best, your user will be mildly inconvenienced or confused by an irrelevant email they received, and at worst you could cause the user to panic and react to the message, potentially costing your user time and money.