The Virtues and Pains of Deleting and Purging Outlook Mail in IMAP AccountsIt's good that Outlook does not forever delete messages immediately in IMAP accounts. That allows for easy undeletion.
It also allows for messages to accumulate, however, and for folders to grow bigger and bigger — until you purge deleted items.
Now, you can do that on your own from time to time (once a week should be enough). Or you let Outlook do it automatically.
Automatic Purging's Dangers
You do lose a bit of the safety net, though: there's no guarantee that a message will be recoverable for a certain time. Whenever you change folders, all the deleted items in the folder you left have just been purged.
Purge Deleted Messages Automatically in Outlook
To have Outlook purge messages marked for deletion automatically when you leave a folder:
- Open a folder in the IMAP account you want to set up for automatic purging.
- Select Edit | Purge | Purge Options... from the menu.
- Make sure Purge items when switching folders while online is checked.
- Click OK.
Remember that Outlook only purges automatically while you are online. Deleted messages in folders you closed while offline will be purged the next time you visit and leave the folder while online.