Do e-mail attachments sent to us become our Property?

You're not violating any laws, no ... however, they also do not become your property. For instance, if I sent you an Anne Gedes artwork image so you could see it, that doesn't mean you can take credit for the creation of the artwork. Anne Gedes holds the copyright and property ownership, you're simply a viewer.

If you personally didn't write it, it's someone else's intellectual property. Here's a site that talks a bit about copyright and the internet (in an easy to read way) http://www.itscopyrighted.com/

no not at all who told you . we can only save them in our account