The biggest problem faced by most of the people using the net is SPAM Mail (Unwanted alias Junk Mail).
There are now very powerful tools available to fight junk.

1. First decide if the message is really "one to one" and private. Most of the e-mails sent and received on the net are public in nature ("One to Many"). For eg. an URL of a news story, Photos, Jokes and so on. If the message is not really private in nature, think of publishing it on the net itself. (Yes, the way I am publishing my thoughts through this http://oksoft.antville.org site) so instead of e-mailing all of you (And adding the spam mail mess) it's easy to publish it here. It gets stored as well. So you don't need to worry about your backups.

2. If the messages are really private (for eg. the recipe of French Fries) you can send and receive your messages using hotmail.
There is an easy way to prevent spam, if you are using Hotmail.
Goto "Options" and choose "Junk Mail Filters" Choose "Exclusive".

E-mail from addresses appearing in your address book will be delivered to your Inbox. All other mail will be delivered to your Junk Mail Folder.

This is the most effective way to avoid spam. However you will have to keep checking the junk mail folder to see if you are not missing any new client or very old friend. (Whose e-mail is not in the address book).

Now you can share this e-mail address with the people whom you really want to keep in touch with. Create another Yahoo! or hotmail ID and use this second e-mail address as your 'public' e-mail address.