Issue with deleted emails reappearing in outlook

When deleting messages out of the junk folder they seem to reappear some time later. This is happening with outlook 2013. Additionally , users are getting duplicate attachments and in some cases their name is in the TO: box twice. When this occurs, each user also has the status of “Updating Junk Email” in the status bar of Outlook. In many cases, if the emails are deleted in the Junk folder in outlook, it will re-appear a few minutes later. This is also happening to people that are using the 'Activity Stream' filter, except with the INBOX folder, activity stream folder seems to be fine in this case.

zextras 2.2.3
zimbra 8.6