How Long Does Gmail Keep Emails?by David Nield
Any email that arrives in your Gmail inbox is there forever, unless you manually delete it. One of the principles behind Gmail is that it gives users enough room to archive all of their messages rather than delete them, so they can be called up through search or labels at any point in the future.
You don't have to worry about your Gmail messages disappearing once they get past a certain age -- the service hangs on to all of your emails no matter how old they are. Every message is counted against your total storage amount (just above 10GB for new accounts as of May 2013), so you can keep as many messages as you like for as long as you like. Choosing to archive a message moves it from your inbox to the All Mail section of Gmail, where it can be recalled via a search or by clicking back through your messages. You might also want to apply labels to your messages to make them easier to find once they've been archived.
Gmail will keep your emails if you want, but you can also delete them manually (or set up a filter to delete them automatically). Clicking the delete button on an email page (the trash can icon) moves that email to the Trash folder, where it's deleted permanently after a period of 30 days. Deleting emails is an option whenever you create a filter; again, messages are moved to the Trash for 30 days. Deleting emails is a useful way of freeing up storage space within Gmail and means the service has less junk to work through when running searches. If Gmail marks emails as spam, these messages are automatically erased after 30 days too, which is why it's worth checking your Spam folder regularly to make sure it hasn't trapped any genuine messages.
Running Out of Room
If you do run out of room within your Gmail account, new emails bounce back to the sender. The emails you already have stored in your inbox and archive are unaffected and won't be deleted unless you specifically erase them. Note that downloading messages through a third-party desktop client doesn't automatically erase them from your Gmail account. You can also choose to purchase additional storage space from Google to store more emails in the cloud. Follow the instructions on the storage space alert for more information.
Google reserves the right to delete your account after a period of nine months if you haven't logged into it in that time. This does put your emails at risk if you are cut off from your account for an extended period of time. Google offers an Inactive Account Manager feature, enabling you to specify a list of trusted contacts who can access and download your messages and other content from Google products after a set period of inactivity. Open the Inactive Account Manager page to set it up.