My case  -These days I send my CV every day to lots of contact , such that it each time send same mail but different To address. In order to avoid re-upload the CV for each sent , I uploaded the CV (doc file) to Google Drive and when I want to send it I do  - right click > Share > Email as attachment. Now, how could I create a fixed body for these mails instead of re-typing it each mail? 
Gmail - how to create fixed mail?
gmail;google drive
In Gmail you can make templates.To enable templates you have to use a Labs Feature called canned responses.Click the Gear Icon in the top right.Select Settings from the menu.Click on the Labs tab. Look for Canned ResponsesEnable It Make Sure you click Save Changes at the bottomTo Set Up a Template:Compose a new message as per normal.Once done, click on the more options dropdown(next to the discard button)Select Canned ResponsesSelect New Canned ResponseGive it a nameDoneTo use a Template:Compose a new messageClick on the more options dropdownSelect Canned ResponsesInsert your templatePlease note: Gmail only allows you to save the body of an email as a template, and not the attachments, but these can be added before sending just as with a normal email.Source