i was trying to access my gmail account

i submited the mail and password but gmail asked for a file download
file called mail from mail.google.com

was surprised so did the download
so gmail was sitting there on the "loading..."
so was wondering since we can learn lot of things from coincidence
what can this teach me?
how do u analyze this

tried opening the file with explorer,notepad...
any idea on what to open the file with

anyone had something like this before

i was able to sign in in my account few minutes ago but on another computer

appreciate ur info