We have a new issue that just cropped up in our environment. It is affecting a variety of people however the issues isn't an everyday occurrence. 

The issue is very much like the following:

https://social.technet.microsoft.com/Forums/office/en-US/5762747a-d616-41d7-993e-b7306f05bdf3/outlook-invite-automatically-moved-to-deleted-items-folder-and-shows-on-calendar-as-tentative?forum=outlook

but its different because the issue doesnt happen every time. This is what is being seen

1. user or resource mailbox sends an invite to a user to accept or whatnot. (email is traceable and delivered to target mailbox)

2. user never sees email in their mailbox, inbox, deleted items, or any mailbox folder.

3. calendar event is marked as tentative on the users calendar.

4. mailbox-search reveals that the mail is in the recover deleted items folder in the mailbox and the message is unread. message was deleted the exact same time of delivery. 

while i have some of my effected users with outlook logging enabled now, the issue has yet to been reproduce able on its own and i do not yet have outlook logs. Technet where should i start looking from here? 

As an update to this I have rebuilt the outlook profile and the issue still happenes

I have disabled EAS on the user and the issue still happens

I have generated outlook logs but no useful information in gleaned. 

I have used MFCMAPI to look for hidden rules and there are none but OOF

I may have to open a ticket to get MSFT to read the .ETL files from the outlook logs to determine whats going on.

After doing a mailbox audit, i found the following information in the logs. This information suggests that outlook/user is soft deleting the message before the message is read.

Operation                     : SoftDelete
OperationResult               : Succeeded
LogonType                     : Owner
ExternalAccess                : False
FolderPathName                : \Inbox
ClientInfoString              : Client=MSExchangeRPC
ClientIPAddress               : 10.30.7.30
ClientMachineName             : 
ClientProcessName             : OUTLOOK.EXE
ClientVersion                 : 15.0.4727.1000
InternalLogonType             : Owner
MailboxOwnerUPN               : JohnDoe@contoso.com
CrossMailboxOperation         : False
LogonUserDisplayName          : John Doe
SourceItemSubjectsList        :  Canceled: Weekly IT Operations Meeting
SourceItemFolderPathNamesList : Inbox
MailboxResolvedOwnerName      : John Doe
LastAccessed                  : 7/15/2015 1:48:04 PM
IsValid                       : True

any ideas?