This procedure applies to LPL mail users only (not PIRL mail users).
login to webmail
click Options (at the top center of the webmail page)
click Folder Preferences
look at the Folder Path field. it should say "mail/".
fill it in, if necessary.
click on Folders
(at the center of the screen above the list of inbox messages),
highlight the folder(s) that you wish to view in webmail
(you can highlight several folders at once by holding down the
ctrl button and clicking them, or holding down the shift button to
highlight a contiguous block in the folders list),
click the Subscribe button.
click the "refresh folder list" link at the top center of the Options page.
click INBOX at the top of the tree on the left side of the page to return to your inbox.