Depending on the smart you have, typically setting up an email address that is associated to that device is important in actually having an account with Gmail. However, one can have a separated "email" service (pop3 etc) assigned to the email app which can be different that the Gmail account setup.
Depending on if your actually activating a smart phone or setting up an alternative email for your smart phone.. Most of the time this can be accomplished by exploring the email settings.. Often its as simple as entering an email which your smart phone has been granted access or using an off site email app like yahoo etc which can be accessed view your app browser.
Please clarify what type of email service your wish to setup.
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