You can even access Gmail when you’re offline, and you can even send Gmail messages when you’re offline. This works by caching the data locally so that even without a connection, your last downloaded email will still load and give you a page to compose new messages.
While this is a good idea if you use Gmail offline on your home computer or other trusted device, it is not so good if you have cached your Gmail messages on a public computer where someone else could read your personal information.
Luckily, Google makes it really easy to clear your Gmail cache and get rid of those offline files once and for all. This includes all offline messages and attachments.
How to Delete Gmail Offline Cache Files
To delete your offline data stored in Gmail, do the following:
Type this into the navigation bar in Chrome: chrome://settings/siteData strong>.
You can navigate to this manually by opening the three-dot menu button in the top-right corner of Chrome and then Institutions in this drop-down menu. Scroll down and click or tap Additionally and then Content Settings from below. Go to page Cookies and then View all cookies and site data †
When this page opens, allow all cookies and other site data to be downloaded in full. This is a complete list of all site data and cookies stored in your Chrome browser.
From here you have two options. First print clear all in the top right corner of the screen. This will erase ALL , so all your offline email is gone. It also removes all other site data from all the other sites you’ve ever visited and takes you out of the list of all the sites you’re currently visiting.
The second option isn’t as destructive, but it can leave behind some data depending on how Google has separated things. Scroll down until you see mail.google.com † Choose an icon bin right next to the web address. This will delete everything coming out of Gmail, including your email backup.
If you choose the first option, you will be asked in a new window to confirm the deletion of all data. Select delete everything to continue deleting all Gmail Offline data, as well as all other cookies stored in Chrome.
Whichever path you choose, return to chrome://settings and choose offline † Uncheck the box Enable Offline Email to disable Gmail offline.
Delete data from Gmail Offline app
If you are still using the Gmail Offline app for Chrome, there is another way to delete offline data.
Visit this page in the Chrome URL bar: chrome://apps
Right-click or press and hold Gmail Offline and select Remove from Chrome…
Select remove when prompted to confirm.