My Macmail and Safari were not working because I downloaded Safari 3.1 to Panther.
I was able to solve this problem without CharlesSoft-Pacifist.
Macmail and Safari are working now. I downloaded Safari 1.2 from the Apple website via Firefox to the desktop. Then I went to the System folder, Opened the Library folder, and then Opened the Framework folder.
Then I put the WEBKIT framework folder in the trash. Then I installed the Safari 1.2. I restarted my Mac and the the Macmail and Safari are working again.
The WEBKIT has been replaced with the original WEBKIT when I installed the Safari 1.2. It is important not to trash the WEBKIT until you have the downloaded Safari 1.2 on the Desktop, because you can not download with Firefox if the WEBKIT is in the Trash.
I have to thank Bob Wood's link for writing how to delete the WEBKIT.
http://macosx.com/forums/mac-os-x-system-mac-software/
268288-localized-string-not-found-safari-firefox.html
I know that many people have had this problem with downloading Safari 3.1 to Panther. The best advice is don't do it.
If you do have this problem, this is a pretty simple way to fix Safari and Macmail.