Originally Posted by WombatDeath
If I save the email, the attachment is saved locally until I delete it. Is that about right?
I won't say emphatically that will be the case. You could save the email, then delete the email from your server, and attempt to open the email and the attachment and get the message "unable to open" or whatever. You might want to test it yourself and see.
I would advise if you have critical documents that must be referenced later, to save that attachment off to the Media Card, etc., and check out one of the document viewers such as BeamBerry or Repligo.