LinuxQuestions.org
Latest LQ Deal: Latest LQ Deals
Go Back   LinuxQuestions.org > Forums > Linux Forums > Linux - Networking
User Name
Password
Linux - Networking This forum is for any issue related to networks or networking.
Routing, network cards, OSI, etc. Anything is fair game.

Notices


Reply
  Search this Thread
Old 06-23-2001, 04:40 PM   #1
jcjollant
LQ Newbie
 
Registered: Jun 2001
Location: NY, USA
Distribution: Mandrake 6.5 or 7.1
Posts: 5

Rep: Reputation: 0
Red face Can't connect sendmail from outside


.
Hi all,

I have a problem with sendmail to which i didn't find the answer for some time.

Problem :
My linux box is both on Internet and Internal network with 2 different NICs.
I can send mails from internal network but I can't from internet.

Configuration :
Let's say my internet @ is i.i.i.i and my private network is p.p.p.p
From the private network, i can telnet sendmail (port 25) on BOTH NICs. From outside, sendmail doesn't seem to be listenning at all (connection timeout).

Could it be some restrictions on port 25 for external connections ?

Thx,
JC
 
Old 06-27-2001, 12:06 PM   #2
LionKing
Member
 
Registered: Jun 2001
Location: Allen, Texas, USA
Distribution: Redhat
Posts: 82

Rep: Reputation: 15
You are using sendmail, right?
Check /etc/sendmail.cf file and locate the line which says DaenonPortOptions, you might have it only allow local net, you should change it to listen to all connections (therefore from outside), it should read as:

O DaemonPortOptions=Port=smtp,Addr=0.0.0.0, Name=MTA
and

And if you have client machines outside your local net to use the SMTP server for outgoing emails (relay), then you must also modify the line in sendmail.cf, so it read like:

# SMTP client options
O ClientPortOptions=Address=0.0.0.0

Let me know what is your final result. regards.
 
Old 06-27-2001, 04:51 PM   #3
nabil
Member
 
Registered: Feb 2001
Location: MI, USA
Distribution: Debian Linux 100% GNU
Posts: 210

Rep: Reputation: 31
He must have used Redhat 7.1.
I know Redhat disabled Sendmail to listen on public IP in 7.1 version by design to strengthen security.
 
Old 06-28-2001, 08:04 AM   #4
jcjollant
LQ Newbie
 
Registered: Jun 2001
Location: NY, USA
Distribution: Mandrake 6.5 or 7.1
Posts: 5

Original Poster
Rep: Reputation: 0
Question

.
Thanks for your replies.

I tried the commands you suggested in sendmail.cf
ClientPortOptions is not recognized by my 8.9.3 sendmail
The "DaemonPortOptions" was regognized though, but i'm still unable to open port 25 from external addresses.

I am running mandrake 6.5 (Linux version 2.2.13-7mdk)

Investigating that problem, I figured out sendmail was not using regular TCP wrapper as other services do. Should I try to include it in inetd scope ? ( As other services don't have restrictions on calling addresses, I would expect the same availability for sendmail)
 
Old 06-28-2001, 05:26 PM   #5
LionKing
Member
 
Registered: Jun 2001
Location: Allen, Texas, USA
Distribution: Redhat
Posts: 82

Rep: Reputation: 15
Do you get any errors, such as connection refused etc?
Do you get a ping rely from the linux machine or traceroute to to it from the external ip?
I ask this because I cannot tell whether you have connectivity problem or you have configuration problem.
 
Old 06-29-2001, 05:58 AM   #6
jcjollant
LQ Newbie
 
Registered: Jun 2001
Location: NY, USA
Distribution: Mandrake 6.5 or 7.1
Posts: 5

Original Poster
Rep: Reputation: 0
This is not a connection problem.
This machine IS accessible from outside (this is my mail server !)
I can open any other services from internet (telnet, httpd, mysqld, ...) it's just that I can't open a connection on port 25 from outside !
 
Old 06-29-2001, 10:36 AM   #7
LionKing
Member
 
Registered: Jun 2001
Location: Allen, Texas, USA
Distribution: Redhat
Posts: 82

Rep: Reputation: 15
I would suggest you to test by initiating a telnet to port 25 to the Linux box, and try to use netstat or tcpdump and observe what is going on with the Linux box. Perhaps from there, you'll be able to ping point where the problem is. Good luck.
 
Old 06-29-2001, 10:39 AM   #8
LionKing
Member
 
Registered: Jun 2001
Location: Allen, Texas, USA
Distribution: Redhat
Posts: 82

Rep: Reputation: 15
Of course you do the telnet test from external network.
 
Old 06-29-2001, 04:00 PM   #9
jcjollant
LQ Newbie
 
Registered: Jun 2001
Location: NY, USA
Distribution: Mandrake 6.5 or 7.1
Posts: 5

Original Poster
Rep: Reputation: 0
.
Of course
 
  


Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off



Similar Threads
Thread Thread Starter Forum Replies Last Post
can anyone tell me how to connect any IMAP server to sendmail ..?? gajaykrishnan Linux - Networking 2 10-26-2005 06:43 AM
Sendmail - PoP soo Slow to connect mac_casey Linux - Newbie 2 01-31-2005 08:11 AM
Can't connect to Sendmail, help r042wal Linux - Software 7 12-12-2004 01:33 PM
client cannot connect to sendmail smtp LetoX Linux - Networking 0 07-06-2004 05:47 PM
How to let sendmail accept the ADSL connect to it SMTP explorer1979 Linux - General 1 07-16-2002 02:52 PM

LinuxQuestions.org > Forums > Linux Forums > Linux - Networking

All times are GMT -5. The time now is 04:22 AM.

Main Menu
Advertisement
My LQ
Write for LQ
LinuxQuestions.org is looking for people interested in writing Editorials, Articles, Reviews, and more. If you'd like to contribute content, let us know.
Main Menu
Syndicate
RSS1  Latest Threads
RSS1  LQ News
Twitter: @linuxquestions
Facebook: linuxquestions Google+: linuxquestions
Open Source Consulting | Domain Registration