title: check mail address whether is under gmail client <Ruby>
body: <p>Gmail able to let users to create whatever email style such as
  account1@gmail.com
  account2@company.com
  account3@university.com</p>
  
  <p>and many more.
  currently, I'm using this contacts gem which is from <a href="https://github.com/liangzan/contacts" rel="nofollow">https://github.com/liangzan/contacts</a> ,
  but when I login using account like account2@company.com..it cannot get my contacts since the email address not @gmail or @googlemail as I read the code.</p>
  
  <p>So,how do I check the email address whether is under gmail address?</p>