Open Provisioning Manager on MPS01, browse to Namespaces -> Hosted Email 2007, open ValidateUserPlanData_ procedure, click on XML tab. Now you must see procedure's source code ;-)).
Comment out very first <execute> node after <procedureData/> node. It must look like this:
<procedure name="ValidateUserPlanData_" description="Validate the contents of a user plan" access="private" type="read" perfEnabled="0" saveDataForRollback="0" auditEnabled="0">
<procedureData/>
<!--
<execute namespace="Error Provider" procedure="SetError">
<when source="data" sourcePath="features/prohibitSendQuota[. > 2147483647 or . < 1000]"/>
<executeData>
<hr>0x80070057</hr><desc>The prohibitSendQuota
parameter must be a positive integer between '1000' and
'2,147,483,647'.</desc>
</executeData>
</execute>
-->
<execute namespace="Error Provider" procedure="SetError">
MPS will ignore your prohibitSendQuota value from plan settings, and you don't have to manually update anything.
