Seeking easy way to download my my.yahoo.com email to my hard drive, so
that I do no have to pay for a larger mailbox.

Hi rick,

  Good day and thanks for your question.
 
  Yahoo mail cannot be retrieved directly onto your harddisk. You will
have to save the individual messages. You can save the messages by
doing the following steps :
1. Log in to your yahoo account and go to your inbox
2. Make sure you are in non-frames mode
3. Open the message you want to save.
4. Save the webpage. In IE, choose the "Web page, complete" option so
that all inline graphics are saved. Don't use Netscape because only
the text is saved and not the images.
5. Attachments will have to be saved separately

Make sure you choose filenames so that you know which file contains
what.

If you feel this is too tedious, you can sign up for servies offering
free POP mail (like http://www.hotpop.com or
http://e-mailanywhere.com), forward the messages from your yahoo
account, and then download them to your computer using a mail client.

If you don't want to leave Yahoo, you can either pay for POP access,
or sign up for multiple accounts and forward them. A word of caution
though - if you sign up for multiple accounts, you must log in ot
those accounts at least once every 30 days to avoid the messages being
deleted

If you have any clarifications, please don't hesitate to ask

Thank you for using this service and have a nice day.

Warm Regards,
aditya2k

Before they had the paid service, you can download your Yahoo mail
through the POP server, but now you have to pay for the POP service.

Their help pages say you can, but only the body of the message (not
the subject and email address), and only as a text file.
http://help.yahoo.com/help/us/mail/read/read-13.html

I haven't tried this, and I'm not sure if it would work, but it looks
to me as though YahooPOPs! would let you download the mail from a
yahoo account into your email software

http://yahoopops.sourceforge.net/

One comment in the support forum seems to suggest not downloading more
than about 100 msgs at a time, or it crashes.

Owain

There is a program which does what you want - free to try, $10 or $20 to buy:

WebMail Assistant
http://www.oneseek.com/webmail.htm