SMTP and the Message Envelope
Here is an example SMTP transaction:
- Client connects to server's SMTP port (25).
- Server: 220 staff.uiuc.edu ESMTP Sendmail 8.10.0/8.10.0 ready; Mon, 13 Mar 2000 14:54:08 -0600
- Client: helo students.uiuc.edu
- Server: 250 staff.uiuc.edu Hello firstname.lastname@example.org [220.127.116.11], pleased to meet you
- Client: mail from: email@example.com
- Server: 250 2.1.0 firstname.lastname@example.org... Sender ok
- Client: rcpt to: email@example.com
- Server: 250 2.1.5 firstname.lastname@example.org... Recipient ok
- Client: data
- Server: 354 Enter mail, end with "." on a line by itself
Received: (from johndoe@localhost)
by students.uiuc.edu (8.9.3/8.9.3) id LAA05394;
Mon, 5 Jul 1999 23:46:18 -0500
Date: Mon, 5 Jul 1999 23:46:18 -0500
From: John Doe <email@example.com>
To: John Smith <firstname.lastname@example.org>
Subject: This is a subject header.
This is the message body. It is seperated from the headers by a blank
The message body can span multiple lines.
- Server: 250 2.0.0 e2DKuDw34528 Message accepted for delivery
- Client: quit
- Server: 221 2.0.0 staff.uiuc.edu closing connection
The sender and recipient addresses used in the SMTP transaction are called
the Message Envelope. Note that these addresses do not need to have
any similarity to the addresses in the message headers!
Mark D. Roth <email@example.com>