I am getting the follwoing error

----- Transcript of session follows -----
... while talking to pbimailc.prodigy.net.:
>>> MAIL From:<nobody@gt_s2.mydomain.com> SIZE=8265
<<< 553 5.1.8 <nobody@gt_s2.mydomain.com>... Domain of sender address nobody@gt_s2.mydomain.com does not exist
501 5.6.0 Data format error

When I am at the server typing
# telenet mydomain.com 25
I can send a mail to joe@aol.com from kevin@mydomain.com.

But from outlook when I send an e-mail to joe@aol.com from kevin@mydomain.com, i get yet another error "550 5.71. saying that relaying is denied"

my files are as follow:
Under /etc/hosts
127.0.0.1 gt_s2 localhost.localdomain localhost
127.0.0.1 gt_s2.mydomain.com
192.168.1.120 gt_s2.mydomain.com

Under /etc/HOSTNAME
gt_s2.mydomain.com

Under /etc/mail/access (Ofcourse I create the db file with makemap hash command)
localhost.localdomain RELAY
localhost RELAY
127.0.0.1 RELAY
MyStaticIP RELAY
192.168.1 RELAY
gt_s2.mydomain.com RELAY

Under /etc/mail/ip_allow
MyStaticIP

Under /etc/mail/local-host-name
mydomain.com
localhost.localdomain
local host
192.168.1.120

Under /etc/mail/name_allow
mydomain.com

Under /etc/mail/relay_allow
mydomain.com
192.168.1.120
gt_s2.mydomain.com

Need be I could place ny sendmail.mc file also. I just don't know what is it that I am doing wrong? Please advise! :study: