As far as I know, https and SSL are no longer usable under Win CE 3.0
(as on the J720
). There are no modern browsers, and there is no way to update IE or other browsers which work under CE 3.0. This is also the case for the browsers available for JLime
(a Linux system which can be installed on the J720
).
However, for email, you might consider using SSH under PocketPutty or from a terminal in JLime. Of course, this means you must have access to an SSH email server. See the discussion in this thread:
https://www.hpcfactor.com/forums/forums/thread-view.asp?tid=18291&start=1&highlight=ssh&highlightmode=1