Search Knowledge Base: How long are deleted items retained? Office 365 and Gmail have different email retention policies for the Deleted Items (Trash) folders and mail that has been permanently deleted. When you delete a message using Outlook, Outlook on the Web, or the Gmail Web App, messages are moved to either Deleted Items or Trash. Office 365: Messages are NOT automatically purged from Deleted Items. Once you permanently delete messages from this folder, it can be recovered for up to 14 days through Recover deleted items within Outlook and Outlook on the Web. Outlook 2010/2016 for Windows Outlook 2016 for Mac Outlook on the Web Gmail (Students only): Messages ARE automatically purged from your Trash folders. Messages that have been in Trash for more than 30 days will be automatically deleted. Once a message has been permanently deleted, it cannot be recovered. Need more help?