When messages go missing, we've found it's almost always down to one of the following issues. Please check carefully to see if any of them could apply. If you still don't know what happened, please contact our support team. We keep detailed logs that allow us to trace exactly what happened to each message received, moved or deleted within the last 7 days.
Most POP clients delete emails off the server once they've downloaded them. Check you don't have a computer or external service (e.g. Gmail or Yahoo) configured to POP download emails from your account.
Discard or forwarding rules could be deleting the messages as they arrive. Check if you have any configured on the Settings → Rules screen. If you use an external email client, it may also have built-in rules/filters. Make sure you check these as well.
Remember that when you select all in a folder or search, not all the selected messages may be visible if there's more than will fit on one screen. If you perform one action on messages, the same messages will still be selected to perform another action.
Check your Trash folder to see if the message has been accidentally deleted. You should also search all folders in case the messages have been accidentally moved to a folder you weren't expecting.
Someone may have compromised you account and deleted your emails. Check your login log (linked from the Settings → Password & Security screen) for suspicious entries. If you see anything odd, immediately change your password and scan your computers for malware. See below for how to recover the deleted emails.
If you accidentally deleted an email, then it should have been moved into the Trash folder. You can retrieve the email by going to your Trash folder and moving the message back to your Inbox.
If the message was permanently deleted within the last 7 days, you can still restore it from our backup.