Link to home
Start Free TrialLog in
Avatar of lungying
lungying

asked on

Sendmail cannot receive internet mail - using dynamic ip serivce by changeip.com

Hi all,

I am using RH8.0 and sendmail 8.12.8.
The sendmail working fine for all internal mail,
and send out to internal also ok.
But i can't receive mail from the internet.
The MX record has been set in the dynamic
dns provider by www.changeip.com.
Telnet to port 25 is ok.
Any ideas?

Thanks a lot!!

Regards,
Peter
SOLUTION
Avatar of jozatan
jozatan

Link to home
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
Start Free Trial
Avatar of lungying
lungying

ASKER

it works fine and give me the following response.
any ideas? thanks.

--------------------------------------------------
220 www.abc.com ESMTP Sendmail 8.12.8/8.12.8; Mon, 31 Mar 2003 21:37:29 +080
0
following is the delay message (will become return message later)
---------------------------------------------------------

>     **********************************************
>     **      THIS IS A WARNING MESSAGE ONLY      **
>     **  YOU DO NOT NEED TO RESEND YOUR MESSAGE  **
>     **********************************************

> The original message was received at Mon, 31 Mar 2003 01:19:22 +0800
> from cmxxx-xxx-xxx-xxx.hkcable.com.hk [xxx.xxx.xxx.xxx]

>    ----- The following addresses had transient non-fatal errors -----
> <ming@abc.com>

>    ----- Transcript of session follows -----
> <ming@abc.com>... Deferred: Connection timed out with abc.com.
> Warning: message still undelivered after 4 hours
> Will keep trying until message is 3 days old
> ----


> Reporting-MTA: dns; udlx1.alumni.ust.hk
> Arrival-Date: Mon, 31 Mar 2003 01:19:22 +0800

> Final-Recipient: RFC822; ming@abc.com
> Action: delayed
> Status: 4.4.1
> Remote-MTA: DNS; abc.com
> Last-Attempt-Date: Mon, 31 Mar 2003 05:59:08 +0800
> Will-Retry-Until: Thu, 3 Apr 2003 01:19:22 +0800
> ----


> From: aaa <aaa@alumni.ust.hk>
> To: ming <ming@abc.com>
> Subject: Re: dfgdf
> Date: 31 Mar 2003 01:19:21 +0800

> ok
Hmmm it looks like remote site is timing out when it's trying to connect to you. Could you send me an e-mail to joro@moon.alliant.edu for test and I'll reply? If you don't want to that's ok but it'll will help me to help you I guess. I would like to see how my system will react and I would like to see messages in my mail server log file as well as messages in mail queue on my machine. I'm running rh8.0 here and no problem communicating internally or with the net, so it could be anything but sendmail. imho
Hmmm it looks like remote site is timing out when it's trying to connect to you. Could you send me an e-mail to joro@moon.alliant.edu for test and I'll reply? If you don't want to that's ok but it'll will help me to help you I guess. I would like to see how my system will react and I would like to see messages in my mail server log file as well as messages in mail queue on my machine. I'm running rh8.0 here and no problem communicating internally or with the net, so it could be anything but sendmail. imho
SOLUTION
Link to home
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
Start Free Trial
nali mu napisah da testva i vsichko bilo nared. gluposti
ASKER CERTIFIED SOLUTION
Avatar of Pablo Allietti
Pablo Allietti
Flag of Uruguay image

Link to home
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
Start Free Trial
after you telnet to port 25 type helo - do you get a response?
Did you checked the DNS settings as I have mentioned above ?
the dns is follow:
xxx.abc.com    10
xxx.abc.com    20

is it ok?
I mean to check if /etc/resolv.conf on the server has correct DNS included
sorry, i don't know the dns setting.
would you mind to give a little bit more details on how to check it? what it supposed to be? thanks.
Simply from the console prompt type :

cat /etc/resolv.conf

If it is not empty, then check if the settings for the DNS servers are correct. It should be sth like :

nameserver IP_OF_DNS_1
nameserver IP_OF_DNS_2
nameserver IP_OF_DNS_3
...

If it is not empty, type :

nslookup -type=MX -sil abc.com

Where abc.com is the mail domain, to which you have sent the above message, which cannot be delivered.

If you receive :
** server can't find abc.com.: NXDOMAIN
this means that simply abc.com cannot be resolved. Then you should change the settings in /etc/resolve.conf and put in the beginning a correct nameserver.
If you get a positive response from nslookup, this means that abc.com is blocking the connection from your server. Probably you are using a ISP, which has some spammers on its servers, or if you are using a dial-up account for the internet connection on your server, abc.com is not accepting connection from dial-up IPs.

Hope this will help


[root@abc root]# nslookup -type=MX -sil xxx.abc.com
Server:         IP_OF_DNS_1
Address:        IP_OF_DNS_1#53

xxx.abc.com mail exchanger = 20 xxx.abc.com.
xxx.abc.com mail exchanger = 10 xxx.abc.com.

[root@abc root]#

but i found that IP_OF_DNS_1 != the ip of my RH. is it the problem?

i think it is not related to my isp, because i successfully run the Argomail server with changeip in winxp. All the send/receive to internet is ok.
Then probably the problem is in your firewall. Do you have any, running on the server ?
Try to make a manual SMTP connection to xxx.abc.com to check if the connection is a problem. Here is a sample, which I have made from my machine to xxx.abc.com, which is actually mail.disney.com. With -> i am marking the response from the server :

[root@xxx root]#telnet mail.disney.com 25
->220 mail.disney.com ESMTP Sendmail Switch-2.2.6/Switch-2.2.4; Thu, 3 Apr 2003 05:15:57 -0800 (PST)
ehlo cmxxx-xxx-xxx-xxx.hkcable.com.hk
->250-mail.disney.com Hello xxx[x.x.x.x], pleased to meet you
250-ENHANCEDSTATUSCODES
250-8BITMIME
250-SIZE 10000000
250-DSN
250-ONEX
250-XUSR
250 HELP
mail from:aaa@alumni.ust.hk
->250 2.1.0 aaa@alumni.ust.hk... Sender ok
rcpt to:ming@abc.com
->250 2.1.5 ming@abc.com... Recipient ok
data
->354 Enter mail, end with "." on a line by itself
test
.
->250 2.0.0 h33DHJP25815 Message accepted for delivery
quit
->221 2.0.0 mail.disney.com closing connection
->Connection closed by foreign host.


If you have sth similar, this means that the connection is ok.
[root@notes root]# telnet xxx.abc.com 25
Trying 127.0.0.1...
Connected to xxx.abc.com (127.0.0.1).
Escape character is '^]'.
220 notes.x24hr.com ESMTP Sendmail 8.12.8/8.12.8; Thu, 3 Apr 2003 23:26:06 +0800ehlo
501 5.0.0 ehlo requires domain address


I can see 2 problems here :

1. Why xxx.abc.com is pointing to 127.0.0.1, is it the same server ?

2. ehlo should be followed by a domain address or simply whatever - e.g. ehlo my_host_name
yes, i am using the same computer.
it works as follow. and i can receive this mail.
but the internet mail still not working.
is it mean that the firewall/dns problem?
-------------------------------------
[root@xxx mail]# telnet xxx.abc.com 25
Trying 127.0.0.1...
Connected to xxx.abc.com (127.0.0.1).
Escape character is '^]'.
220 xxx.abc.com ESMTP Sendmail 8.12.8/8.12.8; Thu, 3 Apr 2003 23:54:00 +0800
ehlo xxx.abc.com
250-xxx.abc.com Hello xxx.abc.com [127.0.0.1], pleased to meet you
250-ENHANCEDSTATUSCODES
250-PIPELINING
250-8BITMIME
250-SIZE
250-DSN
250-ETRN
250-AUTH GSSAPI
250-DELIVERBY
250 HELP
mail from: aaa@aaa.com
250 2.1.0 aaa@aaa.com... Sender ok
rcpt to:ming@xxx.abc.com
250 2.1.5 ming@xxx.abc.com... Recipient ok
data
354 Enter mail, end with "." on a line by itself
test
.
250 2.0.0 h33Fs0QM001455 Message accepted for delivery
quit
221 2.0.0 xxx.abc.com closing connection
Connection closed by foreign host.
[root@xxx mail]#
Ok, let's clarify the situation. You have pasted a message here :

The original message was received at Mon, 31 Mar 2003 01:19:22 +0800 from cmxxx-xxx-xxx-xxx.hkcable.com.hk [xxx.xxx.xxx.xxx]

<ming@abc.com>... Deferred: Connection timed out with abc.com


You are saying that cmxxx-xxx-xxx-xxx.hkcable.com.hk and the server, to which points the mx record of abc.com are one and the same machine ?

You should make this telnet test to the actual server, to which points the mx record of abc.com
i have changed the computer name few days before. and it should be xxx.abc.com now. The cmxxx-xxx-xxx-xxx.hkcable.com.hk was randomly generated by my isp before, and it is not related to the case now. But situation is just the same , the computer name xxx.abc.com got the same error message.
the telnet connect to xxx.abc.com and it is the actual server.
Still is not clear for me what is the exact situation.

As i have understood you have installed a server, let's call it SERVER1. For this server you have dynamic ip service from changeip. On SERVER1 you have sendmail, configured to accept/send internet e-mail.

Then you have tryed to send an e-mail, using SERVER1 to ming@abc.com. MX record of abc.com points to SERVER2.

Are SERVER1 and SERVER2 different machines or one and the same ?
let's call it SERVER1. For this server i have dynamic ip service from changeip. On SERVER1 i have sendmail, configured to accept/send internet e-mail.

And i try to use hotmail to send an email to the mail box on server1 (ming@server1). but i can't receive the email.
What shows iptables -L
[root@xxx root]# iptables -L
Chain INPUT (policy ACCEPT)
target     prot opt source               destination

Chain FORWARD (policy ACCEPT)
target     prot opt source               destination

Chain OUTPUT (policy ACCEPT)
target     prot opt source               destination
[root@xxx root]#
And what shows cat /etc/mail/local-host-names

In this file you must enter all the mail domains, which points to the server.
[root@xxx root]# cat /etc/mail/local-host-names
# local-host-names - include all aliases for your machine here.
xxx.abc.com
localhost
127.0.0.1
com.hk
com
[root@xxx root]#
Hmm, everything looks fine, with one exception - can't receive mails :o)

Ok, final guess :

What shows
cat /etc/sendmail.cf | grep DaemonPortOptions

Should be :

O DaemonPortOptions=Name=MTA

I have try to use O DaemonPortOptions=Name=MTA, but it show error loading sendmail, so i use the following:
-----------------------------------------------
[root@xxx root]# cat /etc/mail/sendmail.cf | grep DaemonPortOptions
O DaemonPortOptions=Port=smtp,Addr=0.0.0.0, Name=MTA
# O DaemonPortOptions=Port=Name=MTA
[root@xxx root]#

The only thing what comes to my mind is to try to make a test telnet session like this above, but from another computer over internet. This will show if there is a firewall problem or sth else. Also to check the nslookup again from outside.
Take a look at the very first suggestion I made and his response. Again. There is nothing wrong with DNS or sendmail in that situation I guess. It's good idea to check mx records from OUTSIDE and debug port 25 from OUTSIDE. OUTSIDE means something different then his LAN/WAN/MAN... from INTERNET. Also I suggested (days ago) to send me an e-mail just to be able to help him faster. Still waiting and he's still debugging :-) Have fun guys. You probably have a lot of spear time.
lungying:
This old question needs to be finalized -- accept an answer, split points, or get a refund.  For information on your options, please click here-> http:/help/closing.jsp#1 
EXPERTS:
Post your closing recommendations!  No comment means you don't care.
Still waiting for answer ...
I think it is not related to the firewall, coz I disabled all the firewall setting already.
I feel sorry for my late response, coz the machine broken up a few weeks before,
and I have no time to upgrade it until now. Anyway, I will try to make a fresh
installation on RH9 again, see whether there are still any problems.
Thank you very much for everyone's efforts to solve this problem.