Example XML Request
<request>
<procedure>
<execute namespace="Managed Plans" procedure="ModifyPlanFeature" impersonate="1">
<executeData>
<preferredDomainController>ad01.fabrikam.com</preferredDomainController>
<featureName>MailboxSize</featureName>
<featureValue>30000</featureValue>
<planName>BasicMail</planName>
</executeData>
</execute>
</procedure>
</request>