Can't open my file

Are you moving a file to mail and trying to open it, or are you moving a file from mail and trying to open it?

I'm not sure why you'd want to move a file to mail and then try to open it.  If you are taking it from mail and wishing to open it then you'd want to double check the file type.  What is the extension? 

What type of file are you trying to open --  PSD, PDF, JPG, TIFF, other?

Please provide some additional information. We'll try to help.

What OS and mail app are you using?

What is the file's extension: jpg, psd...

How do you "move a file to mail it"? Is it moved or copied?

Where is the file you are trying to open: In the mail program? In a folder?

What program are you using to Open the file?

Does this problem occur with other files?