There is a usage problem which prevents me from being able to use the web SmarterMail interface as my primary client: the lack of the option to disable automatic "Mark as Read".
1. First I preview all my messages to answer to priority messages. This automagically marks them as Read, and they disappear from the view if "Only View Unread Messages" is also checked, which generally is, because I have too many of them. As a general rule, when you have important messages you have to act on all of them, so Mark as Read should be disabled by default for safety reasons (Safety > Comfort).
2. Phone preview also marks them as Read, so they disappear from the desktop interface.
3. Please add shortcut keys for "Mark as Read" and "Mark as Unread"
Many of the problems reported with "Mark as Read" keywords can be traced to the default option of Yes.
Please note that the option existed until v9 when it was removed.