My co-worker and I belong to the same G Suite. She received an attachment that she couldn't open (no visible file type). She forwarded the email message to me. I work remote. We are both running Windows 10. I have 7zip installed on my computer, but didn't explicitly invoke it. She doesn't have 7zip.
Reading the email message, I saw one attachment. I couldn't tell if it had a file type extension or not. When I downloaded the ONE attachment, and went to the folder where I stored it, lo and behold, there were two items -- one was a pdf and the other was a mystery file with no extension. After the file name, there were parentheses and the word "omnibus" like this:
clerk response (omnibus)
On a hunch that it was an email message, I edited the file name and added
.eml
Then I edited it with notepad++ and indeed, it was a perfectly legible email message.
My procedure didn't work for her. We did a screen share and I watched her try. It just didn't show up as two items for her.
My guess is that the attachment was an OMB file. If so, what procedure can I come up with for her to be able to open such things without assistance? Does something in her Gmail need to be tweaked? Some setting on her computer? Something needing to be installed?