Sending mail on Fedora Core 4

[Dotan Cohen]

On my home Fedora Core 4 box I run Apache 2.0. Sometimes when I try to
send mail through php nothing is delivered, but I find this in the
logs:

<<< 550-Verification failed for <apache at localhost.localdomain>
<<< 550-unrouteable mail domain "localhost.localdomain"
<<< 550 Sender verify failed

So I changed the only email address in httpd.conf to:
ServerAdmin php at lyricslist.com

But I still get the error and no mail is delivered. I restarted apache
of course, and when that didn't help, I rebooted the machine-
nothing...

What must I configure, and how? Php? Sendmail? Apache?

Thank you in advance.

Dotan Cohen
http://technology-sleuth.com/question/what_are_the_advantages_of_lcd_monitors.html
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