[dba-Tech] Weird gmail issue

I have had three different people try to send me a copy of a single XL
spreadsheet (we're all on a project) and have received none of the emails.
My initial guess was that gmail was seeing this as a potential executable
threat and was blocking it. So I asked one of the three people to zip the
file first and send it. He has done so and I still have not received it.

Does anyone have any idea why this might occur. I forget how to inspect my
filters to see whether anything there is responsible for the blockage

-- 
Arthur