Mail Attachments Missing | Too Small or Zip Issue

NC AIO: 7.11.2
NC Hub: 6 (27.1.5)
Mail App: 3.5.5
OS: Ubuntu 22.02

Everything appears to be working normally. I can send myself files without issue. However – I receive automated reports which are very tiny zipped XML files. These files “disappear” in the NC mail app.

I can see the files when I use a different email client. So I know the files are there.

I suspect that NC is stripping zip files; but I do not have antivirus anything enabled.

Any thoughts or comments are greatly appreciated.

Many thanks.