I'm sure this is a question more for Apple, but I know the Excel community has a vast amount of knowledge...

Is it possible for an .xlsb to still be recognized as a larger file size than it actually is? I've started using .xlsb for a few work files. They have reduced the file size from 26MB to around 4MB.

The problem is, when I email this file to a .me account (iCloud) I get a bounce back saying the file is too large... Even though iCloud has a 10MB email limit. It even shows as a 4MB attachment in the body of the email.

it's happened to multiple .me accounts, but will send fine to GMAIL account and other IMAP accounts...

My only thought is that somehow iCloud is not recognizing the reduced .xlsb file, but still sees it as a large 26MB xls file?

Could this be possible?

Thanks
Rob