| Content-Type: multipart/mixed; boundary="AAA" | |
| From: Mail Delivery Subsystem <[email protected]> | |
| To: [email protected] | |
| This is a MIME-encapsulated message | |
| --AAA | |
| Stuff | |
| --AAA | |
| Content-Type: message/rfc822 | |
| From: [email protected] | |
| To: [email protected] | |
| Content-Type: multipart/mixed; boundary="BBB" | |
| --BBB-- | |
| --AAA-- |