You can't really "block" e-mails. What ever is sent to you will get to you if it is addressed correctly and all the servers let the message pass.
You can however filter unwanted messages to be treated as "junk". You can create rules for junk mail.
If you are using the OS X Mail program, open Mail > Preferences.
Click Rules. Click Add Rule.
Quote from: plume on August 07, 2010, 08:50:28 AM
Good Morning
How do you block unwanted E--Mails
Thank you for your time
Plume
Have you consistently marked the problematic messages as Junk Mail, using the keyboard shortcut, Shift-Command-J, in Mail.app? Mail 4.0 Help Junk Mail Preferences (http://docs.info.apple.com/article.html?path=Mail/4.0/en/cpmlprefjunk.html)
If you still find you receive sufficient SPAM, that Mail.app's built-in
Mark as Junk Mail can't cope, then you
may be a candidate for a 3rd-party SPAM filter.
SpamSieve
http://c-command.com/spamsieve/
I use Mail.app, to which SpamSieve adds two additional menu commands. You can use these "Train as Good" and "Train as Spam" menu items to "teach" SpamSieve what is SPAM. It also has a "Conservative <->Aggressive" sliding control by which you can tweak how aggressively it marks suspect mail as SPAM. I periodically go into the Junk folder to scan for false positives, and if I find any, I use the "Train as Good" menu item to mark these messages for SpamSieve to not touch in the future.
...ben