Problem Summary. When using the Apple Mail client for e-mail, attachments are saved to the local computer by clicking on the save button. By default, they are saved to a downloads folder. At first glance, there appears to be no intuitive way to have additional options for saving.
Problem Solution. Press and hold the save button to reveal a drop-down menu with choices to save all or save individually to an alternate location. This is probably a better method for saving attachments, to simply save items in a permanent location as they arrive by having a place for everything and everything in its place.