Hi,
this is a deliberate security setting of either Netscape or your Email-Provider (which is your provider?? ... and which login-type (Smtp-after POP etc..));
and imho it should not be changed
Whcih netscape version do you have ?
read the help/FAQs of your Mail provider & of Netscape on security/passwords/SMTP/sending Mail
try searching/editing in Netscape->EDIT->Mail settings->SMTP-Server or so..