If you want to send out the same email to multiple people, but want to personalize it for everybody, setting up a mail merge will save you a lot of time. Some email clients like Outlook have a built-in mail merge function, but if you want to use it with Gmail, you’ll have to download a Chrome extension.
http://mashable.com/2016/03/11/personalized-mass-emails-gmail/#X8En7fKvcaqT