# Source: https://documentation.mailgun.com/docs/mailgun/user-manual/sending-messages/test-mode.md

# Sending in Test Mode

You can send messages in test mode by setting the `o:testmode` parameter to either `yes` or `true`. When you do this, Mailgun will accept the message but will not send it. This is useful for testing purposes.

Info
You are charged for messages sent in test mode!