Gmail can sometimes view documents in Google Docs, which you may not want to happen. Here's how to opt out of viewing doc files in Gmail through Google Docs:
Open up the Gmail settings. To do this, click the gear icon on the right side of the Gmail page.
In the Gmail settings, scroll down to the "Content settings" section and find the "Viewing and downloading attachments" section.
Uncheck the "Open doc files with Google Docs viewer" checkbox.
Scroll down and click "Save changes" to confirm the changes.
By following these steps, you should be able to successfully opt out of viewing doc files in Gmail through Google Docs. For more information, you can visit Google's support page (https://support.google.com/mail/answer/145919?hl=en).
