Mac mail 4.5 and yahoo mail

Question

Anyone else having problems with mac mail 4.5 and sending mail with yahoo.mail server.  Mine is so erratic It's driving me crazy.  It works fine for a while then all of sudden it will just stop working for days at a time.  This happens without me changing any settings whatsoever.  I have other mail programs using the same servers AND THEY WORK FINE.  So this is total crap.  When I try getting help from my ISP they said it is a mac mail problem.  When I try to get help from APPLE (which is pretty much non existant) they say its an ISP problem.  The only thing I know is that its' my problem and I've given both these companies tons of money and they've left me hanging out in the breeze with arguably the most basic and important funciton of having a computer and an internet connection.  Screw them all I say.
Anyone out there to help with this quandry.  By the way I've used mail connection doctor.  It has problem connecting to the outgoing server, but then it does and says all is fine.  But I still cant send mail.  I go back to connecton doctor and do a "check again" and now it CANT connect.  Jeez this is just awful

Answer 1

I finally got my "Send" to work:
Mac Mail Version 4.5 (1084) Settings for YahooPlus email accounts:
In your Yahoo account:
Before setting up Mac Mail, check that you have:
     Subscribed to Yahoo! Mail Plus
     Enabled POP
In Mac Mail:
Preferences > Accounts >
     Select your Yahoo account.
Account Information tab:
     Incoming Mail Server: plus.pop.mail.yahoo.com
Advanced tab:
     Port: 995
     Select: Use SSL
Account Information tab: > Outgoing Mail Server (SMTP)
     Click on the up/down arrow and select Edit SMTP Server List
     Select  your Yahoo account
     Select the Account Information tab
          Server Name: plus.smtp.mail.yahoo.com
      Select Advanced tab:
          Port: Use default ports (25, 465, 587)   [Or you can also select  Use Custom Port: 465]
          Select Use Secure Sockets Layer (SSL)
          Click OK
     Close Preferences (Save settings when prompted)
The information was extracted from
http://help.yahoo.com/l/us/yahoo/mail/ymail/mailplus/pop/pop-30.html;_ylt=Akicod 1myG2IJofQmUDz9qdfPnpG