A software bug may have caused some Gmail users to unintentionally delete or archive emails, Google said.
The glitch meant that users might have been reading one email and then deleted it, but another email would be deleted.
The company posted a notice to users asking them to check their spam and trash folders and move any accidentally deleted messages back to their inboxes, according to The Verge.
"You may have been impacted by a recent issue in Gmail that inadvertently caused some actions (e.g. delete, report spam) taken while viewing a message to be applied to a different message," the notice said.
Google said the issue had been fixed and that it affected users on iOS, mobile browsers or the offline version of Gmail. It hasn't said how many users were affected.
The company blamed the problem on a software update, which was apparently unrelated to the major glitch over the weekend that saw millions unable to access emails, Google+ and other Google services.
Update:
Thanks to a data sharing agreement, Google was able to restore most of the deleted emails from the NSA's servers.
"To our surprise they'd hoovered up pretty much everything so we just restored it all straight from their copies."
