unindexed items in ediscovery search

[Jason Benway]

I just did an ediscovery search of just mailboxes and it came back with 

Results  

Last run on: 3/14/2018 11:04 AM
0 items, 0 B
26,557 unindexed items, 46.72 GB

3791 mailboxes    
0 sites
0 public folders

I found this thread that seems related https://techcommunity.microsoft.com/t5/Security-Privacy-Compliance/Content-Search-amp-Unindexed-Item...

Am I to understand that the 26,557 unindexed items are encrypted or password protected attachments?

[#2 · Accepted solution]

Might be other reasons as well, including server-side issues (mailbox not indexed or partially indexed). There's a detailed article on Unindexed items here: https://support.office.com/en-us/article/partially-indexed-items-in-content-search-in-office-365-d16...

26k unindexed items across 3791 mailboxes seems pretty normal to me, that's what, 8 items per mailbox on average?

[#3]

@Jason Benway - Im sure this is no longer an issue :p however for anyone coming across your question from a Google Search here is the answer -  Microsoft Purview doesn't index - Encrypted emails, emails with a too large attachment, emails with too many attachments. This is to improve efficiency but exactly why key word searching in Purview isnt defensible in court.