Content-Type: text/plain; format=flowed
Subject: Delivery failure, mail too large
From: "Mail Daemon"<postmaster@system>

Hi,
  Your message to "<rcpt>" cannot be delivered properly because it's too large!

Below is the original mail information:
   Time:    <time>
   From:    <from>
   To:      <rcpt>
   Subject: <subject>
   Parts:   <parts>
   Length:  <length>
