You could trace it down to the originating IP, but unless it was a matter of personal security, most provider's won't give this much merit. Even getting it to the originating IP won't reveal much unless it is considered a security concern, the provider will need something in the way of "official" backing to reveal that information. Since anyone can get a gmail address in this day and age, you will be hard pressed to even be able to trace it. Someone whom wanted to hide their identity and went to these lengths would probably fake everything and post from a public computer (like at the library). Like others said, I would write it off.
