Explain Mac to PC attachments: "Part 1.3", etc?

[RumMunkey]

When I send attachments from my Mac to a PC, I notice some extra attachments are tacked on when they are received on a machine running Windows. These show up as text files named "Part 1.3" and "1.5" and so on.

I understand that this is essentially a blip in the translation between Macs and PCs, but not much more than that.

I know nothing is wrong and nothing is missing, and the reader can safely disregard the extra attachments, but the problem is I know that... the recipient doesn't, so I still get asked about these "missing" pictures.

So, I have 2 questions really:

1) What is really happening here? I'd like to understand it better.

2) Can this be turned off, or can I do something to the Mac mail app that will send "Windows Friendly" attachments?


EDIT: Ah, never mind. Changing my Google search words I found there is an option to "always send Windows friendly attachments". My question is does "Always" mean "always"? Like if I send pictures from iPhoto to Mail using iPhoto's "Mail" button, and I have the global "Windows friendly" option on, will it still do it? I Assume so...

 

[MisterMe]

When I send attachments from my Mac to a PC, I notice some extra attachments are tacked on when they are received on a machine running Windows. These show up as text files named "Part 1.3" and "1.5" and so on.

... What is really happening here? I'd like to understand it better.

... My question is does "Always" mean "always"? Like if I send pictures from iPhoto to Mail using iPhoto's "Mail" button, and I have the global "Windows friendly" option on, will it still do it? I Assume so...

Those "Parts" are an artifact of the multipart MIME standard for email attachments. Read more about it here.

The answer to your latter question is that "always" means "always."

 

[RumMunkey]

Thanks, but I'm discovering that it doesn't mean always.

I have the global option set to "Always send Windows friendly attachments", but for some reason when I use the "Email" button to send selected photos from iPhoto, these extra attachments still show up in Windows machines (which is everybody in my family but me).

However when I select a single photo and "export" it to the desktop, then open Mail and write a new message and attach the photo to it myself, the attachment is Windows friendly.

So it seems that something in the moving of the pictures from iPhoto to Mail disregards my "Windows Friendly" preference.