When composing an email in Apple Mail. Unless the receivers are all use Apple Mail, then please make sure you put all the attachments at the end of message.

Apple Mail display certain types of attachments inline. So when you compose an email as <some text> + <attachments> + <more text>, Apple Mail will encode the whole message as:<some text> + <encoded attachments> + <encoded text attachment of the more text>

If you got such an email and read it in Apple Mail, it will be decoded correctly and still keep the attachment displayed between texts. But for other email clienst, it just <some text> + 2 attachments ! This will bother you more when you have a signature defined. There will always be some text after the attachments until you manually rearrange them.

If you put all attachments at the end of message. Apple Mail will encode correctly.

So, to be friendly to other clients, esp. Windows clients. Please keep the following 2 options selected:

1. Edit->Attachments->Always Send Windows Friendly Attachments

2. Edit->Attachments->Always Insert Attachments at The End of Message