sendmail query.

[aruns_s]

hi All,

May be I am asking a stupid question here.
In our setup, mails are getting forwarded to a relay server before passing on to messaging server.In of our server, i cannot find any entry for relay server in sendmail.cf,that is.,
entry "DS" in sendmail.cf is blank. Still server is able to deliver mails to outside world... just wondering how this is happening..

[Hutch Mumbai]

1. DNS server giving you the MX record.
2. /etc/hosts resolving for Relay in your domain.

Do a
sendmail -v -d9.99 -d38.99 user_name@domain.com < /dev/null

and see the results. Post it if you still cant understand it though its very explanatory.

cheers!
Anshu

[Anshumali]

1. DNS server giving you the MX record.
2. /etc/hosts resolving for Relay in your domain.

Do a
sendmail -v -d9.99 -d38.99 user_name@domain.com < /dev/null

and see the results. Post it if you still cant understand it though its very explanatory.

PS: by mistake i used different id to post last response.

cheers!
Anshu

[whiteknight]

Arun,

It is because you are in DNS and you have a domain name, so i will go through the root server.

WK

[aruns_s]

$ /usr/sbin/sendmail -v test@test.com < /dev/null
test@test.com... Host unknown (Name server: test.com: host not found)
/home/unixsupp/t003957/dead.letter... Saved message in /home/unixsupp/t003957/dead.letter
--------------------------------------------
But one of my client is telling that he is getting the mails from this server. As i said earlier, there is no entry for the smtp relay server in sendmail.cf.

How did the he receive the mail eventhough there is no smtp server configured?

Thanks

[Anshumali]

Reminds me of Spoofing? quite possible by mailx -r
please run the command which i mentioned with actual domain name, if it still doesn't resolve and message goes in dead letter in debug data check with security guys!

What is there is the header file of email received at your client? It may show you the actual ip.

Anshu