An email, usually very short, sent for the purpose of testing whether the email system is working. The sender's purpose may be:
- to find out whether the sender's outgoing email is configured correctly
- to troubleshoot the end-to-end connection between a sender and recipient

If the sender is able to find his solution with no response from the recipient, the test email will usually contain a terse instruction like "ignore this email."

If the sender needs a response from the recipient in order to complete the test, then the test email will say something like "let me know if you got this."

When you eat dirt for the first time and leave your family to build a shack in the woods