89a788ff_Zarafa_Archiver__Meaning_and_usage
[Setting] cleanup_follow_purge_after [Type] yes/no [Default] no [Required] No [Meaning and usage] 
Specify that items that are cleaned up from the archive are at least the age that is specified in setting purge_after. This is to avoid messages being deleted from the archive when they were deleted from the primary store by a delete operation. Note that setting this to yes will cause a cleanup run to seemingly do nothing. A rule of thumb is to set this to the same value as delete_enable. So when delete_enable is set to yes, make sure cleanup_follow_purge_after is also set to yes.
Zarafa Archiver
Meaning and usage