To backup your folders in Webmail (HORDE) follow simple backup procedure.

Step 1: Login to your webmail account using full email address
Step 2: Once logged in locate and click on FOLDERS icon
Step 3: Select folder you would like to backup to your local disk
Step 4: Choose action DOWNLOAD FOLDERS (you may download as file or zip format)
Step 5: When pop up window opens, select SAVE (make sure you download backup file to known destination on your local disk in case you need to restore)

To restore saved files (FOLDERS) at any time, click on FOLDER icon and choose action IMPORT MESSAGES.