mail comes back to root?

[kevkim55]

I'm glad we finally understand each other.

Yeah ! We sure do ! Just wanted to hear a word from you !

[pavlo_7]

This turns out to be an interesting thread.
So far we agreed that one way to send out email is to relay through existing, valid SMTP server (ex. ISP's SMTP server).

Now, what would be needed if Lakshmipathi wanted to use the second approach? I mean, just like you suggested, replacing localhost.localdomain on his computer with fully qualified domain name.

Clearly, using any name will not work. It must be unique and registered domain name which should resolve to static IP on the Internet.
Otherwise, it could not be looked up, or could be considered as spoofing if the name already exists on Internet and resolves to another IP.

Then, the computer must be be configured as SMTP server (and as POP/IMAP server if he wants to receive email).

Is there something else that I'm missing here ? This basically means running your own email server.

[Lakshmipathi]

hi guyz,
thank your valuable inputs and here is
few more info about my settings ,

[root@pc021698 etc]# hostname
pc021698.xyz.com

i wonder what's the next error really mean?

[root@pc021698 etc]# host pc021698.xyz.com
Host pc021698.xyz.com not found: 3(NXDOMAIN)

and when i try

host xyz.com
;; Truncated, retrying in TCP mode.
xyz.com has address 10.238.82.10
xyz.com has address 10.227.30.92
xyz.com has address 10.237.5.95
xyz.com has address 10.226.33.35
...(and more addresses here)
...

[root@pc021698 etc]# cat /etc/resolv.conf
; generated by /sbin/dhclient-script
nameserver 10.232.5.20
nameserver 10.237.5.79
search xyz.com

[pavlo_7]

i wonder what's the next error really mean?

[root@pc021698 etc]# host pc021698.xyz.com
Host pc021698.xyz.com not found: 3(NXDOMAIN)

it means there is no host named "pc021698" at xyz.com

[root@pc021698 etc]# hostname
pc021698.xyz.com

[root@pc021698 etc]# cat /etc/resolv.conf
; generated by /sbin/dhclient-script
nameserver 10.232.5.20
nameserver 10.237.5.79
search xyz.com

It seems you are trying to use a name which belongs to someone else. xyz.com is a registered domain on the Internet, and what you are trying to do is spoof this name. This is not going to work. This name resolves to IP different than yours, and that's why it's not finding your computer "pc021698" in that domain (it is searching the real xyz.com).