This document discusses how to send an email attachment using Mule ESB's SMTP connector. It describes how to configure a Mule flow to read a file from a source directory, attach it to an email message, and send the email using SMTP. The key components used are the file inbound endpoint to read the file, attachment transformer to attach it to the email, and SMTP outbound endpoint to send the email. Running the example flow results in the attached file being sent as an email attachment to the specified recipient address.