Troubleshooting a mailbox that will not archive in Enterprise Vault

I've got users that are out of scope and are not configured but they're part of the same exchange server. 

some of these users cannot archive using outlook. Only our key employees have vault setup for them. The rest are to use outlook to archive but for some reason they cannot. I've done all the troubleshooting steps to see if its because of modifed date or add-on preventing this but for some reason, the archive file will only grow to 265KB. something is preventing them from archiving and i'm assuming its vault....