LinuxQuestions.org
Did you know LQ has a Linux Hardware Compatibility List?
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 06-29-2005, 05:05 AM   #1
goonfui_wong
Member
 
Registered: Jun 2005
Posts: 37

Rep: Reputation: 15
sendmail server unable to receive external mail


Hi,

I've set up sendmail server with the domain name, say
linux4u.com.

and I edit the sendmail.mc file

dnl # define(`UUCP_MAILER_MAX', `2000000')dnl
dnl # DAEMON_OPTIONS(`Port=smtp,Addr=127.0.0.1, Name=MTA')dnl
dnl # FEATURE(`accept_unresolvable_domains')dnl
LOCAL_DOMAIN(`linux4u.com')dnl
MASQUERADE_AS(`linux4u.com')dnl


and "m4"

I can receive mail from root to user@linux4u.com.
and send mail to my external mailbox e.g gmail.

However, I cannot receive email sending from external mailbox.
e.g. gmail to user@linux4u.com

Why? kindly advise.
 
Old 06-29-2005, 10:01 AM   #2
Looking_Lost
Senior Member
 
Registered: Apr 2003
Location: Eire
Distribution: Slackware 12.0, OpenSuse 10.3
Posts: 1,120

Rep: Reputation: 45
It's a long while since I used sendmail but:

The address you are using i.e smtp.linux4u.com resolves to your external ip address?

You have port 25 open in your firewall ?

Your firewall is routing traffic sent to port 25 to the local address 127.0.0.1 as it looks as though sendmail is only listening on 127.0.0.1 and not your external ip address.
 
Old 06-29-2005, 07:36 PM   #3
goonfui_wong
Member
 
Registered: Jun 2005
Posts: 37

Original Poster
Rep: Reputation: 15
Hi,

Thanks you.

yap... you are right, this is because of firewall protection.

However, I'm no the firewall guy. Someone have "force" the ip address
to point to correct one.... this is what I heard.
Please correct me if I wrong.

I expected, the mail should able to deliver .... and take time to route.
As until now I didn't receive any "Mail Delivery Subsystem" from
mailer-daemon@gmail.com.

Thank you again.

Regards,
 
Old 06-29-2005, 07:49 PM   #4
mcd
Member
 
Registered: Aug 2003
Location: Boulder, CO
Distribution: Slackware, RHEL, CentOS
Posts: 825

Rep: Reputation: 33
it depends on how your mail server connects to the internet. in most cases, it will be on a local network behind a firewall and connect to the outside world through a gateway (in my case a simple linksys router). your external IP address will then point to that gateway, and anyone requesting to open a connection on port 25 with your IP address will be talking to the gateway and not your mail server (which is actually 192.169.1.120 or whatever). so you need to set up port forwarding for port 25. in my case it was as simple as logging into my router and entering a couple numbers. it depends on how your network is set up.
 
Old 06-29-2005, 08:49 PM   #5
goonfui_wong
Member
 
Registered: Jun 2005
Posts: 37

Original Poster
Rep: Reputation: 15
Hi,

Thanks again.

Your explanation always right. There have a linksys router.
And someone have been configure it. A bundle of external mails
coming to my account, which send by yesterday.

However, I no sure how to do it...willing to learn it.
And I check from the linux machince with "nslookup" for user@acha.com

example:
nslookup acha.com

Non-authoritative answer:
Name: acha.com
Address: 202.71.138.147

It seem the domain name able to find.


rgds,
 
Old 06-30-2005, 03:12 PM   #6
mcd
Member
 
Registered: Aug 2003
Location: Boulder, CO
Distribution: Slackware, RHEL, CentOS
Posts: 825

Rep: Reputation: 33
ok, so you need to know 2 things. the internal ip addresses of your gateway and your mail server. routers are normally 192.168.1.1, so that should be easy. open up a browser like firefox or IE explorer and put that in the url bar and hit enter. it should ask you for a user name and password, which you should enter. then you want to look for a tab called "forwarding". on my router i first have to click on "advanced" and then "forwarding". then i tell it to forward port 25 to 192.168.1.65, which is my mail server. save the changes and exit. you should be all set.
 
Old 06-30-2005, 09:56 PM   #7
goonfui_wong
Member
 
Registered: Jun 2005
Posts: 37

Original Poster
Rep: Reputation: 15
Hi,

Thanks you my friend

I manage to do it.
 
Old 07-01-2005, 02:15 AM   #8
mcd
Member
 
Registered: Aug 2003
Location: Boulder, CO
Distribution: Slackware, RHEL, CentOS
Posts: 825

Rep: Reputation: 33
 
  


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
Sendmail - Can receive external, no local mail though macdonalder Linux - Software 2 11-18-2005 03:04 AM
sendmail and external mail server levand Linux - Networking 10 12-17-2004 09:45 AM
configure sendmail to use external mail server Drogo Linux - Software 0 09-16-2004 09:16 PM
Postfix can't receive external mail kantoboy Linux - Networking 4 09-03-2004 11:57 AM
Cannot receive inbound external emails with Sendmail jimwillsher Linux - Newbie 12 02-09-2004 12:50 PM


All times are GMT -5. The time now is 01:17 PM.

Main Menu
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
identi.ca: @linuxquestions
Facebook: linuxquestions Google+: linuxquestions
Open Source Consulting | Domain Registration