Hello,
First let me thank you all for the support I got with my port 25 problem. After a lot of searching and reconfiguring it seems to be working now. I would appreciate it if you all sent me an email to congratulate me at johndoe@leeuwis.org (also for testing purposes, if it bounces please sent a copy to the mailadres in the header.)
To help people in the future I made a little howto on the subject, maybe someone can place it on the e-smith or contribs.org site.
Niels
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TROUBLESHOOTING PORT 25 FOR DUMMIES
After installing the e-smith server 5.6 (first time install (newbee))
I encountered a problem with qmail not receiving emails. Propably
I'm not the only one with this problem so here is a litte HOWTO on
the subject.
Situation:
mailserver (mydomain.org) situated at home, placed in the DMZ
(DeMilitarized Zone) after firewall, connected with the internet
through ADSL.
Problem:
outgoing mail is being delivered without any problems
incoming mail returns to sender with the message 'server not responding'
(in my case I was able to receive email that originated from my own
provider (uplink) that should have given me a clou)
Troubleshooting steps:
1. check of qmail is listening on the e-smith server (netstat -a -n)
you should see something like 0.0.0.0:25 LISTENING (The :25 is
important, you will have a long list)
2. check of qmail is responding from your internal network
(telnet 'server IP' 25) (start telnet from the commandline and
remember to put a space between your server IP and 25)
If it's working you wil get an answer from your server saying
220 servername.mydomain.org
If step 1 and 2 give no result you have a qmailproblem on your server
or a bad network connection. More info on qmail at
http://www.qmail.org3. check if your firewall is configured properly, yoo should forward
port 25 and 110 (sometimes 143) to the server IP and open these ports
for externel access.
4. check if your server is visible from the internet, goto
http://www.grc.com and choose 'probe my ports' If it's okay the test should say both port 25
and 110 OPEN. If both ports are blocked or stealthed go to step 5, the
problem is your firewall. If only port 25 is stealthed or blocked the problem
is with your uplink (goto 6)
5. remove the firewall and connect the server directly to the modem (you need
to reconfigure but that is what troubleshooting is for ...., run step 4
again, if you see port 110 open this time get the manual for your firewall,
the solution is in there.
6. here is the hard part, for me, I had to try to get the correct
configuration information from the helpdesk (they send me an email
back with instructions howto setup outlook express 3 times
)
To prevent spamming most providers block all SMTP traffic (port 25)
that is not originated from their downlinks or designated to one of
their downlinks. The problem is that yourdomain.org is not known by
the server so it rejects the message. To get this working you have
change your MX records (at the site you registered your domain).
your MX records should look something like this:
mydomain.org 10 smtp.mydomain.org
mydomain.org 20 relay.provider.com
(set smtp.mydomain.org also at your e-smith server)
In your DNS be sure to point mydomain.org to the correct existing
class A IP adress.
After changing the records let it boil for 24 hours and then it should work.
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