Gmail is one of the world's largest email providers, with around 1.5 billion active users globally.
It's built on the idea that email can be intuitive, efficient and useful - and for the most part that's true.
But there's one issue that comes up time and again, and it's to do with users accidentally archiving emails when they're scrolling through their inbox on their iPhone or Android device.
This is because the touch gesture for archiving an email from the Gmail inbox is swiping it to the side.
If you're scrolling through your inbox with your thumb, it's very easy to accidentally swipe horizontally rather than vertically, resulting in the email being archived by mistake.
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Gmail gives you the option to reverse the action by tapping the "undo" button at the bottom of the screen, but this only appears for a few seconds after you've archived the message.
There is no folder in Gmail for archived messages, so if you're too slow to tap the button, it may seem like you've lost your email forever.
But archived messages aren't actually deleted. You can retrieve them at any time - you just need to know how.
If you know who the sender of the email was, or can remember the subject line, you can simply tap the magnifying glass icon in the top right hand corner and type in the search term.
When you search in Gmail, your results will include any messages that have been archived, so it should be relatively easy to find.
Alternatively, tap the three horizonal lines in the top left hand corner of the screen to open the Gmail menu, and then tap "All emails".
This will open up a folder containing all your messages, including those that have been archived, so you can scroll through and find the one you archived accidentally.
To move archived messages back to your inbox, open up the email in question, tap the three dots in the top right hand corner, and select "Move to inbox".
The "Inbox" label will be reassigned to that message, and when you return to your Gmail inbox, the message should be there.
