Case item goes missing from the Ongoing/Resolved Cases folder after adding/updating an email or attachment
This may be due to breaching of the size limitation of an Outlook item as set by your Exchange policy, that is, consider a scenario, where a case becomes invisible (without any warning) as soon as the total amount of data in the case (inclusive of attachments and inline images) exceeds a certain admin specified size, say, 20 MB. This size (e.g., 20 MB) is the max an Outlook item is allowed to grow. When more data or attachments are added to the Outlook item (case), it violates the exchange policy and is removed or moved to temporal location in Exchange as might have specified by your administrator.
Microsoft Outlook by its nature, does not set any limitation in the number of attachments a particular item (email or appointment) can have. Please note that, Team helpdesk addin does not perform jobs related to storage or items in Exchange Team helpdesk folders. Nor does it check the size of the individual case item or warn the user if the size exceeds. The Team Helpdesk folders are just like normal Exchange folders, and all the typical Outlook rules/Exchange policies still apply.
Another possibility for disappearance of certain case items could be due to breach of certain standards/limitations that were put in place by the exchange admin. For instance, if your admin had set a ‘Public Folder’ Age limit whereby, when an age limit in days is specified, the applicable content that has reached the limit is permanently removed. To understand this folder age limit scenario, please refer to this article – http://blogs.technet.com/b/sbs/archive/2010/09/20/why-does-some-of-my-public-folder-content-seem-to-disappear-automatically.aspx