Exchange 2013 Search-Mailbox not returning expected results (On-premise)

[dayzd]

Hi, people who are more experienced with Exchange that I am!

 

I'm testing out some scripts to search all my users' mailboxes and have come up wanting.

 

I've sent myself a few emails with a few attachments in, each containing a keyword I'd later search for. Some of these have been returned correctly, but a few have not. In particular, Excel .xlsx files.

 

To test further, I emailed myself a second spreadsheet called 'testexcelthesecond.xlsx' and it contains two words: 'helicopter' and 'discombobulate'. I've run the following search, but the ResultItemsCount is 0:

 

Search-Mailbox -Identity dayzd -SearchQuery "(kind:contacts OR email OR journals OR meetings OR notes OR posts OR tasks) AND (attachment:testexcelthesecond.xlsx) OR (attachment:discombobulate) OR (attachment:helicopter)" -EstimateResultOnly

 

However, if I search for this email's subject, it is found. If I search for other words I know exist in other Excel attachments I have (real data, not test), they are discovered. It's just not reading this particular Excel file.

 

Are there any tricks I'm missing?