Remove archive not working using openarchive plugin

Hello…

In my application i have install openarchive 1.0.4 plugin to show recent conversation between users.

message retrieval is working great…but i can’t delete recent conversations.

when i fire to removing all collections…

<iq type='set' id='remove'`` xmlns='jabber:client'><remove xmlns='urn:xmpp:archive'/></iq>

server returns following

<iq type="error" id="remove" to="test@domain/e3322df0">
     <error code="501" type="cancel">
     <feature-not-implemented xmlns="urn:ietf:params:xml:ns:xmpp-stanzas"/></error>
</iq>

how can i implement remove conversation feature in my application if removal feature is not implemented in openarchive plugin ?

Many Thanks…