The title says it all. Does anyone have experience with sending uncompressed folders to people using different operating systems? Can attached folders be opened on Windows?

1 Answer 1


When you attach a folder to a email in Mail, even thought it looks like an individual folder in the email, both in the composed email and then the sent email, nonetheless the contents of the folder when sent, is zipped into a single .zip archive that is base64 encoded for transport. It is the .zip file that's received by others and there should not be a problem with them accessing it regardless of Host OS.

Looking at the actual .emlx file, here is an excerpt showing the attachment as a .zip file that is actually an "untitled folder" selected to be attached.

Content-Disposition: attachment;
    filename="untitled folder.zip"
Content-Type: application/zip;
    name="untitled folder.zip"
Content-Transfer-Encoding: base64

When I received the file in a different email client it was shown as an attachment not the folder as shown in Mail under OS X.

When opened in the other email client it contained the files that were in the "untitled folder" that was attached to the email that was sent.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .