How to configure SMART_HOST For sendmail

decenter · 12-23-2012, 05:16 AM

Hello,

I'm trying to use sendmail to send email via a SMTP server, since the server is in internal network. The SMTP server is in public network. I used this documentation

http://www.dnsexit.com/support/mailrelay/sendmail.html

and configured SMART_HOST. But, when I send email, the SMTP server rejects the email due to the fact that it is coming of root@localhost.com

Code:

(reason: 550-Verification failed for <root@localhost.com>)

   ----- Transcript of session follows -----
... while talking to mail.server.com.:
>>> DATA
<<< 550-Verification failed for <root@localhost.com>
<<< 550-The mail server could not deliver mail to root@localhost.com.  The account or domain may not exist, they may be blacklisted, or missing the proper dns entries.

But I used telnet to send email, it works and comes in to the inbox.

Code:

[root@localhost mail]# telnet 127.0.0.1 25
Trying 127.0.0.1...
Connected to 127.0.0.1.
Escape character is '^]'.
220 localhost ESMTP Sendmail 8.14.4/8.14.4; Sun, 23 Dec 2012 15:40:38 +0530
HELO server
250 localhost Hello localhost [127.0.0.1], pleased to meet you
MAIL from:tempid@id.com
250 2.1.0 tempid@id.com... Sender ok
RCPT to:id@id.com
250 2.1.5 id@id.com... Recipient ok
DATA
354 Enter mail, end with "." on a line by itself
Subject:Test mail vid record
from:tempid@id.com
to:id@id.com
test email not working?
.
250 2.0.0 qBNAAcZZ002661 Message accepted for delivery
quit
221 2.0.0 localhost closing connection
Connection closed by foreign host.

Any light on this?

Ser Olmy · 12-23-2012, 06:59 AM

Quote:

Originally Posted by decenter

and configured SMART_HOST. But, when I send email, the SMTP server rejects the email due to the fact that it is coming of root@localhost.com

Code:

(reason: 550-Verification failed for <root@localhost.com>)

   ----- Transcript of session follows -----
... while talking to mail.server.com.:
>>> DATA
<<< 550-Verification failed for <root@localhost.com>
<<< 550-The mail server could not deliver mail to root@localhost.com.  The account or domain may not exist, they may be blacklisted, or missing the proper dns entries.

It clearly says that mail cannot be delivered to root@localhost.com, which makes sense if the domain doesn't exist.

You could capture the traffic with tcpdump to verify that the recipient address is indeed the problem, rather than the sender.

decenter · 12-23-2012, 10:19 PM

The issue is not that. I'm sending mail from a localhost via sendmail (configured SMART_HOST). The mail server rejects the email from localhost and send a failure message back and even that is getting rejected.

njainn · 12-23-2012, 10:45 PM

Can u ping the server in outside n/w , if not then check gateway and add the n/w in the routing table then it will work
route add -net n/w name/netmask device-name

decenter · 12-24-2012, 12:50 AM

No. Routing issue is not there. I checked this document: http://www.cyberciti.biz/faq/configu...-a-smart-host/

In that document, they didn't say about where to enter SMTP usrernames and password.