mdbox + alt storage + purge = wtf ...

All,

Is there a bug in doveadm purge ? Configured alt storage and move messages in inbox to the alternate path all well and good. However, after deleting some messages and running a purge on the mailbox found that all messages got recopied over to primary location. I guess this maybe because its re-writing the file and ditching the purged mail .. but shouldnt it keep a track that they were located on alt storage path ??

rgds

Matt