[Receive Mail] The email I moved to Trash has been deleted. How long are emails stored?
When deleted, mails in each Mail Box will move to Trash. Based on your settings, emails in Trash will be deleted automatically after 7 or 15 days from the receipt date. 
However, emails in Inbox, Sent, and Draft will never be automatically deleted unless you delete them manually. 

Please note that emails automatically deleted from Trash cannot be restored. 
(The automatic deletion period is calculated based on the receipt date of the relevant email, not from the date when the email was moved to Trash. )

Please note that emails received before the set period (7 or 15 days) will be automatically and permanently deleted when moved to Trash.