(1) Are the following assumptions correct?
In general, locally installed email clients like Outlook, outlook express and eudora don't require logging in each time with a username & password (altho you must configuire them with correct servers, logins, and pws, to get mail).
Some webmail sites (like hotmail and gmail), can remember your webmail acct login/pw and let you go straight to your inbox URL without re-entering it each time.
Other webmail sites, like yahoo, require a fresh login at least once every 10 hours or so.
And sometimes, locally installed software associated with an ISP will store your login/pw and log you straight into your ISP provided inbox. e.g. AOL, compuserve, and sbcglobal.net (paid yahoo dsl email accts).
(2) Is there software that will do this with all kinds of webmail, without reference to this or that ISP?
(3) I notice that some of these ISP-related "logging-in" software apps appear in the list of the "default email program" dropdown box list. Sometimes they work, and sometimes they don't. By "work", I mean, will they open a correctly addressed email msg WHEN you click on an email hyperlink or or choose File / Send / Page by Email (IF the webmail page doesn't require a fresh login). Some do, some don't -- for me. Is this consistent with your experience?