When you are away from your Gmail account, like on a vacation, you can set up a vacation responder to automatically notify people that you won't be able to get back to them right away. When people send you a message, they'll receive an email response containing what you've written in your vacation auto-reply.
Step 1: Login your Gmail account (please refer here to open one if you do not have an account yet);
Step 2: In the Gmail account, click the "Setting" button from the right-top corner;
Step 3: Click the "Settings" command from the drop-down list;
Step 4: Click the "General" tab in the settings menu;
Step 5: Scroll the cursor down to the "Out-of-Office AutoReply" section, check "Out of Office AutoReply on".
Set up the first day and the last day of the message, then type the message in the message box;
Step 6: Click the "Save Changes" button at the bottom.