This article describes how to backup your mailbox by using the Horde webmail application.
Backup Export
2) Confirm that you are using Horde Webmail by selecting the drop down menu in the top right of the page.
3) Right click on the folder you would like to export from the left navigation pane. Select "Export".
4) Choose the format, and press "OK".
Backup Import
2) Confirm that you are using Horde Webmail by selecting the drop down menu in the top right of the page.
3) Right click on the folder you would like to import to, from the left navigation pane. Select "Import".
4) Select the file, then push "OK".