mails not coming thru'

mails not coming thru'

[Varun Pabrai]

Hello,
       My server is on Mandrake 10.1 off.
eth0 is gateway with static IP connected to 512Kbps DSL.
eth1 is LAN.

I went to webmin ->networking -> linux firewall.
I did a NAT on eth0.

Then I added rules using packet filtering for 
sending and recieving mails as follows :

accept if network protocol is TCP and destination port is 110

accept if network protocol is TCP and destination port is 25

saved and applied configuration and rebooted.

But I am not able to send or recieve mails on client 
machines. Why ?

Anybody has any idea please help.

Thanks

Varun

Re: mails not coming thru'

[Samuel Jean]

Varun Pabrai wrote:

>Then I added rules using packet filtering for 
>sending and recieving mails as follows :
>
>accept if network protocol is TCP and destination port is 110
>  
>
add: accept if network protocol is TCP and source port is 110

>accept if network protocol is TCP and destination port is 25
>  
>
add: accept if network protocol is TCP and source port is 25

>saved and applied configuration and rebooted.
>
>But I am not able to send or recieve mails on client 
>machines. Why ?
>  
>
What happens is (I guess) your mailserver receives the packet, but when
answering, it gets dropped because the source port is now 25.

Same thing for your POP server.

>Anybody has any idea please help.
>  
>
HTH,

Samuel