# Table of contents:

• Introduction
• Client/Request
  • Acknowledgement Types
• Server/Response
• Examples
  • Client initiated
    • Unacknowledged message
    • Acknowledged message
    • Negative-Acknowledged message
    • S-Type acknowledgement message
    • Data message
    • Poorly formatted data message
    • Invalid context (Notification Server)
  • Server initiated
    • Notification Server
      • Initial profile
      • Initial e-mail configuration
      • New e-mail
      • Mailbox activity
      • System message
    • Switchboard Server
• Known changes

# Introduction

MSG is a command introduced with MSNP2.

It is a Notification and Switchboard Server command, WITH a request and WITH a response payload.

Used to transfer MIME-headered data to other parties, whenever that be you or other users.

# Client/Request

This command can only be sent in a Switchboard session.

MSG TrID [ U | N | A | D ] length
payload

# Acknowledgement Types

• U: Unacknowledged, no response is sent.
• A: Acknowledged, a ACK response is sent if the message is sent successfully to all users, or a NAK response if it was not, or there are no users to send to.
• N: Negative-Acknowledged, a NAK response is sent if the messaged failed to send successfully.
• S: Unknown. Sent for invite messages since (unknown version). Possibly an exclusive ACK-only mode for Successful?
• D: Data, a version of Acknowledged that also has a response of error 282 if the message was poorly formatted.

Acknowledgement Type D is defined since MSNP9.

Where length is the size (in bytes) of the payload.

Where payload is the body of the message, usually containing a MIME-Version header and a Content-Type.

# Server/Response

MSG user-handle friendly-name length
payload

Where user-handle is either the senders's handle, or Hotmail, if sent from the Notification Server itself.

Where friendly-name is either the URL-encoded Friendly Name of the sender, or Hotmail, if sent from the Notification Server itself.

Where length is the size (in bytes) of the payload.

Where payload is the body of the message, usually containing a MIME-Version header and a Content-Type.

# Examples

# Client initiated

# Unacknowledged message

C: MSG 1 U 76
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8

unacknowledged

# Acknowledged message

NOTE: the enum used for this (MMSGTYPE_ALL_RESULTS (2)) seems to imply that this also accepts a NAK response...

C: MSG 2 A 74
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8

acknowledged
S: ACK 2

# Negative-Acknowledged message

C: MSG 3 N 86
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8

negatively acknowledged?
S: NAK 3

# S-Type acknowledgement message

Since... we don't actually know... Possibly MSNP8?
NOTE: This could be ACK-only? Not sure, this uses MMSGTYPE 3 internally...

C: MSG 4 S 73
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8

possibly success-only?
S: ACK 4

# Data message

Since MSNP9.
NOTE: It is unlikely that the server would allow anything that isn't the type of application/x-msnmsgrp2p.

C: MSG 5 D 73
MIME-Version: 1.0
Content-Type: application/octet-stream

data message
S: ACK 5

# Poorly formatted data message

Since MSNP9.

C: MSG 6 D 75
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8

data message?
S: 282 6

# Invalid context (Notification Server)

Inherited from being an unimplemented command.

C: MSG 7 U 0

Server disconnects client.

# Server initiated

# Notification Server

# Initial profile

NOTE: This profile is from MSNP2, later versions have longer initial profiles.

S: MSG Hotmail Hotmail 95
MIME-Version: 1.0
Content-Type: text/x-msmsgsprofile; charset=UTF-8
LoginTime: 1726321960

# Initial e-mail configuration

NOTE: In MSNP2 only, the type of the initial e-mail configuration was application/x-msmsgsemailnotification, which was changed in MSNP3 to text/x-msmsgsinitialemailnotification.

S: MSG Hotmail Hotmail 221
MIME-Version: 1.0
Content-Type: text/x-msmsgsinitialemailnotification; charset=UTF-8

Inbox-Unread: 1
Folders-Unread: 0
Inbox-URL: /cgi-bin/HoTMaiL
Folders-URL: /cgi-bin/folders
Post-URL: http://www.hotmail.com

# New e-mail

NOTE: In MSNP2 only, the type of the e-mail notifications was application/x-msmsgsemailnotification, which was changed in MSNP3 to text/x-msmsgsemailnotification, and also added the id header for automatic Passport authentication, and the Post-URL was also changed from http://www.hotmail.com to the Passport md5auth.srf endpoint provided by your account's Passport server or of a Hotmail law server.

S: MSG Hotmail Hotmail 359
MIME-Version: 1.0
Content-Type: text/x-msmsgsemailnotification; charset=UTF-8

From: Example User
Message-URL: /cgi-bin/getmsg?msg=MSG1728932553.00&start=1&len=12&curmbox=ACTIVE
Post-URL: https://loginnet.passport.com/ppsecure/md5auth.srf?lc=1033
Subject: =?"us-ascii"?Q?Just saying hello.?=
Dest-Folder: ACTIVE
From-Addr: example@hotmail.com
id: 2

# Mailbox activity

S: MSG Hotmail Hotmail 146
MIME-Version: 1.0
Content-Type: text/x-msmsgsactivemailnotification; charset=UTF-8

Src-Folder: ACTIVE
Dest-Folder: ACTIVE
Message-Delta: 1

# System message

NOTE: There may be other types of system messages, Type 1 is for a server shutdown message, Arg1 in this case would be the minutes before the server is set to shutdown.

S: MSG Hotmail Hotmail 88
MIME-Version: 1.0
Content-Type: application/x-msmsgssystemmessage

Type: 1
Arg1: 5

# Switchboard Server

S: MSG example@hotmail.com example%20user 73
MIME-Version: 1.0
Content-Type: text/plain;charset=UTF-8

acknowledged

# Known changes

• MSNP3: Switchboard: Added support for the X-MMS-IM-Format header.
• MSNP9: Switchboard: Added acknowledgement type D.