Yes, that's correct, if you accidentally delete items in you inbox AND empty the trash you can still recover your deleted email from your Webmail interface!
For up to 14 days, it is possible for users to recover email messages even after they have been purged from the Trash folder. To do so, login to Cloud Webmail:
and perform the following steps:
1. Right click on the Trash folder
2. In the context menu, click Recover Deleted Email…
3. Select the message(s) that you want to recover
4. Click Recover to Folder.
5. Select the folder you want to move the messages to
When you see the confirmation “Message(s) Recovered”, you are done.