I gather from your last posts that you use Aweb as your browser and you downloaded AmiSSL 2.0 and installed it. The last post in your previous thread suggested installing AmiSSL 1.x because the current version of Aweb doesn't work correctly with AmiSSL 2.0. Have you tried this yet? I believe that version 1.x can be downloaded
here.
Alternatively you could purchase
IBrowse 2.3 which should work with AmiSSL 2.0.
If none of this works, please give more information about the problem you are having. What error does the browser give you or what happens when the connection attempt is made? Are you attempting to use yahoo's secure server or the standard server for login? What OS version are you using? etc.
Another alternative you may wish to consider (if all else fails and you're really only concerned with getting yahoo email to work.) is using a seperate email client like YAM or OS3.5's AmigaMail to access your yahoo mail account instead of loging in via the web.
Cheers