SMTP Port 25

S

slander

Verified User
Joined
Mar 11, 2013
Messages
14
My host does not block port 25. Via root terminal, trying to telnet to localhost using port 25 fails, as well as externally.

Email is not working because of this.

root@gator:~# cat /etc/exim.conf|grep -i smtp_ports
daemon_smtp_ports = 25 : 587 : 465
# see also daemon_smtp_ports above
root@gator:~#

(from server side)

root@gator:~# telnet localhost 25
Trying 127.0.0.1...
telnet: Unable to connect to remote host: Connection refused
root@gator:~#

root@gator:~# netstat -l|grep 25
tcp 0 0 *:2571 *:* LISTEN
tcp6 0 0 [::]:2571 [::]:* LISTEN
root@gator:~#


Suggestions?
 
I've got it working to a point. However, still not able to receive email.

root@gator:~# lsof -i -P|grep exim
exim 5558 mail 3u IPv6 275270 0t0 TCP *:25 (LISTEN)
exim 5558 mail 4u IPv4 275271 0t0 TCP *:25 (LISTEN)
exim 5558 mail 5u IPv6 275272 0t0 TCP *:587 (LISTEN)
exim 5558 mail 6u IPv4 275273 0t0 TCP *:587 (LISTEN)
exim 5558 mail 7u IPv6 275274 0t0 TCP *:465 (LISTEN)
exim 5558 mail 8u IPv4 275275 0t0 TCP *:465 (LISTEN)
exim 7414 mail 9u IPv4 285491 0t0 TCP 198.167.139.136:25->mta164.mailmime.com:56451 (ESTABLISHED)
exim 7414 mail 10u IPv4 285491 0t0 TCP 198.167.139.136:25->mta164.mailmime.com:56451 (ESTABLISHED)
exim 7481 mail 9u IPv4 285784 0t0 TCP 198.167.139.136:25->mx39.linkmime.com:56289 (ESTABLISHED)
exim 7481 mail 10u IPv4 285784 0t0 TCP 198.167.139.136:25->mx39.linkmime.com:56289 (ESTABLISHED)
exim 7482 mail 9u IPv4 285790 0t0 TCP gator:25->cdptpa-omtalb.mail.rr.com:56821 (ESTABLISHED)
exim 7482 mail 10u IPv4 285790 0t0 TCP gator:25->cdptpa-omtalb.mail.rr.com:56821 (ESTABLISHED)
root@gator:~#

Gmail shows a "Delayed" status email when sending email to [email protected] with this message:


Delivery to the following recipient has been delayed:

[email protected]

Message will be retried for 2 more day(s)

Technical details of temporary failure:
The recipient server did not accept our requests to connect. Learn more at http://support.google.com/mail/bin/answer.py?answer=7720
[(10) mail.nondisclose.tld. [myipgoeshere]:25: Connection refused]
 
Try to debug your EXIM...

Runs an daemon with debug enabled:
$ /usr/sbin/exim -bd -d+all

Simulate an incoming connection from IP "1.1.1.1":
$ /usr/sbin/exim -bh 1.1.1.1

Also check your EXIM logs at:
/var/log/exim/mainlog
/var/log/exim/paniclog
/var/log/exim/processlog
/var/log/exim/rejectlog
 
The mainlog is full of this.

2013-08-17 13:29:55 TLS error on connection from mail-pb0-f51.google.com [209.85.160.51] (SSL_accept): timed out
2013-08-17 13:29:55 TLS client disconnected cleanly (rejected our certificate?

Incoming test:

root@gator:/var/log/exim# /usr/sbin/exim -bh 1.1.1.1

**** SMTP testing session as if from host 1.1.1.1
**** but without any ident (RFC 1413) callback.
**** This is not for real!

>>> host in hosts_connection_nolog? no (option unset)
>>> host in host_lookup? yes (matched "*")
>>> looking up host name for 1.1.1.1
>>> IP address lookup using gethostbyaddr()
>>> IP address lookup failed: h_errno=1
>>> host in host_reject_connection? no (option unset)
>>> host in sender_unqualified_hosts? no (option unset)
>>> host in recipient_unqualified_hosts? no (option unset)
>>> host in helo_verify_hosts? no (option unset)
>>> host in helo_try_verify_hosts? no (option unset)
>>> host in helo_accept_junk_hosts? no (option unset)
220 MYHOST ESMTP Exim 4.73 Sat, 17 Aug 2013 14:02:56 +0000
^Z
[1]+ Stopped /usr/sbin/exim -bh 1.1.1.1
root@gator:/var/log/exim#

However, in the debug terminal...

14:00:00 20405 Connection request from 75.180.132.120 port 40081
14:00:00 20405 interface address=198.167.139.130 port=25
14:00:00 20405 search_tidyup called
14:00:00 20405 2 SMTP accept processes running
14:00:00 20405 Listening...
14:00:00 20500 sender_fullhost = [75.180.132.120]
14:00:00 20500 sender_rcvhost = [75.180.132.120]
14:00:00 20500 Process 20500 is handling incoming connection from [75.180.132.120]
14:00:00 20500 host in host_lookup? yes (matched "*")
14:00:00 20500 looking up host name for 75.180.132.120
14:00:00 20500 DNS lookup of 120.132.180.75.in-addr.arpa (PTR) succeeded
14:00:00 20500 IP address lookup yielded cdptpa-omtalb.mail.rr.com
14:00:00 20500 gethostbyname2(af=inet6) returned 4 (NO_DATA)
14:00:00 20500 gethostbyname2 looked up these IP addresses:
14:00:00 20500 name=cdptpa-omtalb.mail.rr.com address=75.180.132.121
14:00:00 20500 name=cdptpa-omtalb.mail.rr.com address=75.180.132.122
14:00:00 20500 name=cdptpa-omtalb.mail.rr.com address=75.180.132.123
14:00:00 20500 name=cdptpa-omtalb.mail.rr.com address=75.180.132.124
14:00:00 20500 name=cdptpa-omtalb.mail.rr.com address=75.180.132.125
14:00:00 20500 name=cdptpa-omtalb.mail.rr.com address=75.180.132.126
14:00:00 20500 name=cdptpa-omtalb.mail.rr.com address=75.180.132.127
14:00:00 20500 name=cdptpa-omtalb.mail.rr.com address=75.180.132.33
14:00:00 20500 name=cdptpa-omtalb.mail.rr.com address=75.180.132.120
14:00:00 20500 checking addresses for cdptpa-omtalb.mail.rr.com
14:00:00 20500 75.180.132.121
14:00:00 20500 75.180.132.122
14:00:00 20500 75.180.132.123
14:00:00 20500 75.180.132.124
14:00:00 20500 75.180.132.125
14:00:00 20500 75.180.132.126
14:00:00 20500 75.180.132.127
14:00:00 20500 75.180.132.33
14:00:00 20500 75.180.132.120 OK
14:00:00 20500 sender_fullhost = cdptpa-omtalb.mail.rr.com [75.180.132.120]
14:00:00 20500 sender_rcvhost = cdptpa-omtalb.mail.rr.com ([75.180.132.120])
14:00:00 20500 set_process_info: 20500 handling incoming connection from cdptpa-omtalb.mail.rr.com [75.180.132.120]
14:00:00 20500 setting SSL CTX options: 0x800
14:00:00 20500 tls_certificate file /etc/exim.cert
14:00:00 20500 tls_privatekey file /etc/exim.key
14:00:00 20500 Initialized TLS
14:00:00 20500 required ciphers: ALL:!ADH:RC4+RSA:+HIGH:+MEDIUM:-LOW:-SSLv2:-EXP
14:00:00 20500 host in tls_verify_hosts? no (option unset)
14:00:00 20500 host in tls_try_verify_hosts? no (option unset)
14:00:00 20500 Calling SSL_accept
14:00:00 20500 SSL info: before/accept initialization
14:00:00 20500 SSL info: before/accept initialization
^[[B^[[B^[[B^[[B^[[B^[[B14:03:06 20476 SSL info: SSLv2/v3 read client hello A
14:03:06 20476 LOG: MAIN
14:03:06 20476 TLS error on connection from mx34.linkmime.com [38.103.22.34] (SSL_accept): timed out
14:03:06 20476 LOG: MAIN
14:03:06 20476 TLS client disconnected cleanly (rejected our certificate?)
14:03:06 20476 search_tidyup called
14:03:06 20405 child 20476 ended: status=0x0
14:03:06 20405 1 SMTP accept process now running
14:03:06 20405 Listening..
 
On the incoming connection emulation, you should simulate an SMTP dialogue and preferably use a real IP.

At my example, <- is for incoming data, and -> is for what you should send.

Example using Google IP/hostname and starting a TLS session:

$ /usr/sbin/exim -bh 209.85.160.51

Code: 
<- **** SMTP testing session as if from host
<- ... 
<- 220 MYHOST ESMTP Exim 4.73 Sat, 17 Aug 2013 14:02:56 +0000
[B]-> EHLO mail-pb0-f51.google.com[/B]
<- >>> test.com in helo_lookup_domains? no (end of list)
<- ...
<- 250 HELP
[B]-> STARTTLS[/B]
<- ...

If you cannot start an encrypted session, check your EXIM certificate:

Code: 
$ cat /etc/exim.conf |grep 'tls_privatekey'  
(probably /etc/exim.key)
$ cat /etc/exim.conf |grep 'tls_certificate'
(probably /etc/exim.cert)

If you want to regenerate it:

Code: 
$ /usr/bin/openssl req -x509 -newkey rsa:1024 -keyout /etc/exim.key -out /etc/exim.cert -days 9000 -nodes
$ chown mail:mail /etc/exim.key
$ chmod 644 /etc/exim.key
$ chmod 644 /etc/exim.cert
$ /etc/init.d/exim restart
 
Tested as such:

root@gator:/etc# /usr/sbin/exim -bh 209.85.160.51

**** SMTP testing session as if from host 209.85.160.51
**** but without any ident (RFC 1413) callback.
**** This is not for real!

>>> host in hosts_connection_nolog? no (option unset)
>>> host in host_lookup? yes (matched "*")
>>> looking up host name for 209.85.160.51
>>> IP address lookup yielded mail-pb0-f51.google.com
>>> gethostbyname2 looked up these IP addresses:
>>> name=mail-pb0-f51.google.com address=209.85.160.51
>>> checking addresses for mail-pb0-f51.google.com
>>> 209.85.160.51 OK
>>> host in host_reject_connection? no (option unset)
>>> host in sender_unqualified_hosts? no (option unset)
>>> host in recipient_unqualified_hosts? no (option unset)
>>> host in helo_verify_hosts? no (option unset)
>>> host in helo_try_verify_hosts? no (option unset)
>>> host in helo_accept_junk_hosts? no (option unset)
220 MYHOST ESMTP Exim 4.73 Sat, 17 Aug 2013 16:34:02 +0000
EHLO mail-pb0-f51.google.com
>>> host in pipelining_advertise_hosts? yes (matched "*")
>>> host in auth_advertise_hosts? yes (matched "*")
>>> host in tls_advertise_hosts? yes (matched "*")
250-MYHOST Hello mail-pb0-f51.google.com [209.85.160.51]
250-SIZE 20971520
250-PIPELINING
250-AUTH PLAIN LOGIN
250-STARTTLS
250 HELP
STARTTLS
>>> host in tls_verify_hosts? no (option unset)
>>> host in tls_try_verify_hosts? no (option unset)
220 TLS go ahead
LOG: TLS error on connection from mail-pb0-f51.google.com [209.85.160.51] (SSL_accept): error:140760FC:SSL routines:SSL23_GET_CLIENT_HELLO:unknown protocol
LOG: TLS client disconnected cleanly (rejected our certificate?)
^Z
[6]+ Stopped /usr/sbin/exim -bh 209.85.160.51
root@gator:/etc#


Regenerated certificate, same result.
 
Don't worry about the issued TLS error, it's because you are under an unencrypted session.

Apparently your EXIM is not properly routing the connections on port 25:

Code: 
$ [B]telnet 198.167.139.130 25[/B]

Trying 198.167.139.130...
Connected to 198.167.139.130.
Escape character is '^]'.
EHLO test.com
Connection closed by foreign host.

Code: 
$ [B]telnet 198.167.139.130 587[/B]

Trying 198.167.139.130...
Connected to 198.167.139.130.
Escape character is '^]'.
220 gator.rkserv.co ESMTP Exim 4.73 Sat, 17 Aug 2013 17:00:50 +0000
EHLO test.com
250-gator.rkserv.co Hello srv12hv.unihostbrasil.com.br [96.31.65.178]
250-SIZE 20971520
250-PIPELINING
250-AUTH PLAIN LOGIN
250-STARTTLS
250 HELP
quit
221 gator.rkserv.co closing connection
Connection closed by foreign host.

I don't know what do you have changed in your EXIM configurations, maybe
something is wrong. If it's ok for you, update your EXIM configs with the
latest versions:

http://help.directadmin.com/item.php?id=51
 
The exim.conf file should have been unchanged. However, updating it has worked. Thanks very much.
 
You must log in or register to reply here.
Back
Top