In several occasions I found myself needing to test solutions that send emails to various locations. Sometimes it's events or alerts, and sometimes it's other sorts of notifications or periodic information.
Specifically for the case of testing an appliance or a black-box product that is supposed to send emails, in most cases people resort to ugly solutions like having a single mailbox for testing or creating an LDAP/AD account that serves the tests. This is far from ideal, as it doesn't isolate emails from different tests and requires some IT intervention.
I decided to write a small server app that can help improve testing in such cases. Mailboxer is a server app intended to be deployed on a VM or on a small server in your datacenter. The user can then open virtual mailboxes using a simple REST web interface, and have the server store emails sent to these mailboxes. You can get all messages received by the mailbox, or just the unread ones, making many email testing scenarios a mere few REST requests away.
Check out the source at the Github page, and don't hesitate to leave feedback, pull requests or issues.