honestly, you will probably have some trademark problems, you know you are using google's service name.
Now that you have posted in the forum, expect a cease and desist letter from google (google might ask you to pay $100000 in the email as well) within few weeks.
I would agree with the recommendations, maybe just delete that domain and forget about it, it is too dangerous, gmail is copyright of google. hackgmail suggest something sinister.
I didn't want to take risks. Donated! Thanks However Searching on Sedo for domain starting with "gmail" and .com extension: Your search returned 99 matching domains!
I wouldnt be that sure about legal issues. Google had to switch to googlemail themselves in some countries due to trademark issues