This article will guide on how to set the setting to move the deleted email to trash.
1. Login to your webmail via URL: http://yourdomain.com/webmail.
2. Click read your mail using Horde.
3. Select the Setting Icon and go to Preferences then click on Mail on the top function as below.
4. Select "Deleting and Moving Messages".
5. Tick on option "Move deleted messages to your Trash mailbox instead of marking them as deleted in the current mailbox?" and click "Save" to save the setting.