Notifications

In the MSN protocol, notifications are the primary means of receiving MSN Mobile messages. They are received with the IPG command and are in the XML format as follows.

<NOTIFICATION id="Number (Message Counter?)" siteid="111100400" siteurl="http://mobile.msn.com/">
    <TO name="Email Address">
        <VIA agent="mobile"/>
    </TO>
    <FROM name="tel:+Mobile Phone Number|Email Address"/>
    <MSG pri="1" id="1|407">
        <CAT Id="110110001"/>
        <ACTION url="2wayIM.asp"/>
        <SUBSCR url="2wayIM.asp"/>
        <BODY lcid="1033">
            <TEXT>Message Text</TEXT>
        </BODY>
    </MSG>
</NOTIFICATION>

The name attribute of the FROM tag may contain either a mobile phone number with the prefix "tel:+" or an email address, depending on whether the sender has their mobile phone set up with MSN Mobile or not.
The id attribute of the MSG tag is a 1 if it is a normal message, but a 407 indicates that the message you just sent was too long for the mobile device and the TEXT tag is then empty.