What are you thinking? Even my child knows Gmail is Google, there is no way you can use it as "generic" domain. I hope that help.
Katherine gave you a strong feedback about the domain.
Really? "Gmail" can only be for the service Google offers?
There seems to be a mailing service by the same name that operated under the domain gmail.de until Google acquired the rights to the name in 2012... after failing to do so with an offer of 250,000 Euros in 2006.
http://www.domainnamenews.com/legal-issues/google-settles-dispute-over-gmail-de-after-8-years/10291
In its current state of a parked page, for your domain, OP, I am of the opinion that you are asking for trouble.
The German entrepreneur had a legitimate use for the name, that he was using before Google ever introduced their service. You need to have a similarly compelling argument if you don't want this name taken away forcibly.
There are some plausible abbreviations for the term...
"Guerrilla Marketing Association of Illinois" - GMAIl
"Greater Metropolitan Atlanta Institute of Learning" - GMAIL
"Government of Massachusetts Internal Library" - GMaIL
Those are just a few off the top of my head. It's unlikely, but not impossible, in my non-qualified, non-lawyer opinion, that this name can be kept without a fight.