I use Verizon DSL service. I have tried to setup a mailserver, but
have failed so far. My expertise with linux is rather limited. Hope
someone can .

1) Postfix is installed, and configured (ok I think)
2) If I do "telnet localhost 25" -- I get proper response. But if I do
"telnet ipaddress 25" it just dies without a response.
3) I am able to send out mail successfully

for example, mail xyz@yahoo.com works
4) However, if I mail back xyz@aname.dnsalias.org from xyz@yahoo.com
-- I get a
error after a day that SMTP connection was not estblished.

5) I have verified with or without shorewall running, and port 25 is
allowed
6) I have allowed port 25 on my linksys router also.
7) I do have a DSL modem, but it is all in default configuration
8) I can repeat step 2, from another computer on the local network.

telent 10.10.10.161 25 works from a windows xp machine.

Any clues? Is it that Verizon is blocking my incoming 25 port? Or is
it a problem with DYNDNS settings ( I dont have a dedicated DNS).

Thanks

Run this command to make sure Postfix is listening on 0.0.0.0

# netstat -an | grep :25
tcp 0 0 0.0.0.0:25 0.0.0.0:* LISTEN

If it's not take a look in /etc/postfix/main.cf: inet_interfaces = all

If netstat looks okay, then take a look at the network port security on your box,
perhaps iptables.

--
Greg



gb_xxxx@verizon.net wrote:
> I use Verizon DSL service. I have tried to setup a mailserver, but
> have failed so far. My expertise with linux is rather limited. Hope
> someone can .
>
> 1) Postfix is installed, and configured (ok I think)
> 2) If I do "telnet localhost 25" -- I get proper response. But if I do
> "telnet ipaddress 25" it just dies without a response.
> 3) I am able to send out mail successfully
>
> for example, mail xyz@yahoo.com works
> 4) However, if I mail back xyz@aname.dnsalias.org from xyz@yahoo.com
> -- I get a
> error after a day that SMTP connection was not estblished.
>
> 5) I have verified with or without shorewall running, and port 25 is
> allowed
> 6) I have allowed port 25 on my linksys router also.
> 7) I do have a DSL modem, but it is all in default configuration
> 8) I can repeat step 2, from another computer on the local network.
>
> telent 10.10.10.161 25 works from a windows xp machine.
>
> Any clues? Is it that Verizon is blocking my incoming 25 port? Or is
> it a problem with DYNDNS settings ( I dont have a dedicated DNS).
>
> Thanks

Thanks Greg. The netstat output looks ok. How can I check the iptables
for port security though?



On Sat, 01 Apr 2006 04:48:42 GMT, Greg Hackney <hackney@swbell.net>
wrote:

>
>Run this command to make sure Postfix is listening on 0.0.0.0
>
># netstat -an | grep :25
>tcp 0 0 0.0.0.0:25 0.0.0.0:* LISTEN
>
>If it's not take a look in /etc/postfix/main.cf: inet_interfaces = all
>
>If netstat looks okay, then take a look at the network port security on your box,
>perhaps iptables.

gb_xxxx@verizon.net wrote:
> Thanks Greg. The netstat output looks ok. How can I check the iptables
> for port security though?

Sorry, but I'm not familiar with the Mandriva distribution.

On RedHat, the firewall rules are in /etc/sysconfig/iptables

--
Greg