Resolution:
Example Notify Operation:

Message-Id: &lt59219.1004639859008.JavaMail.xyz@xyz>
Mime-Version: 1.0
Content-Type: multipart/mixed; boundary=961626.1004639858898.JavaMail.xyz.xyz
Content-Name: mime
Content-Length: 821

--961626.1004639858898.JavaMail.xyz.xyz
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: binary
Content-Name: header

&ltheader>
        &ltfrom&gtmachine1</from>
        &ltto&gtmachine2</to>
        &ltoperationID&gtWidget Inventory/1.0/haveWidget</operationID>
        &ltoperationType&gtnotify</operationType>
        &lttransactionID&gt1</transactionID>
</header>
--961626.1004639858898.JavaMail.xyz.xyz
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: binary
Content-Name: msg

<?xml version = "1.0" encoding = "UTF-8" standalone = "no"?>
<!DOCTYPE WidgetAvailable SYSTEM "WidgetAvailable.dtd">
&ltWidgetAvailable>
        &ltwidgetName&gtACME gadget</widgetName>
        &ltaskPrice validity = "good-till-notice"&gt100</askPrice>
</WidgetAvailable>