Question : Sendmail & POP via IPTABLES

Pretty basic issue for a noob. Here goes...

I have sendmail setup on a linux FC3 box. When I turn iptables off I can send/receive mail in outlook fine. When I start up IPTABLES on the linux FC3 box, I can send but I cannot receive on this particular account hosted on my sendmail box. I added a line that matches the line for port 25 below for port 110 and TCP via WEBMIN but I am missing something. I have not studied IPTABLES or IPCHAINS yet so I tried to cheat my way through with WEBMIN but I still cannot get her to let loose.  SUGGESTIONS??





Below is my IPTABLES readout:

 /etc/init.d/iptables status
Table: nat
Chain PREROUTING (policy ACCEPT)
target     prot opt source               destination

Chain POSTROUTING (policy ACCEPT)
target     prot opt source               destination

Chain OUTPUT (policy ACCEPT)
target     prot opt source               destination

Table: mangle
Chain PREROUTING (policy ACCEPT)
target     prot opt source               destination

Chain INPUT (policy ACCEPT)
target     prot opt source               destination

Chain FORWARD (policy ACCEPT)
target     prot opt source               destination

Chain OUTPUT (policy ACCEPT)
target     prot opt source               destination

Chain POSTROUTING (policy ACCEPT)
target     prot opt source               destination

Table: filter
Chain INPUT (policy ACCEPT)
target     prot opt source               destination
RH-Firewall-1-INPUT  all  --  0.0.0.0/0            0.0.0.0/0

Chain FORWARD (policy ACCEPT)
target     prot opt source               destination
RH-Firewall-1-INPUT  all  --  0.0.0.0/0            0.0.0.0/0

Chain OUTPUT (policy ACCEPT)
target     prot opt source               destination
           tcp  --  0.0.0.0/0            0.0.0.0/0           tcp

Chain RH-Firewall-1-INPUT (2 references)
target     prot opt source               destination
ACCEPT     all  --  0.0.0.0/0            0.0.0.0/0
ACCEPT     icmp --  0.0.0.0/0            0.0.0.0/0           icmp type 255
ACCEPT     esp  --  0.0.0.0/0            0.0.0.0/0
ACCEPT     ah   --  0.0.0.0/0            0.0.0.0/0
ACCEPT     udp  --  0.0.0.0/0            224.0.0.251         udp dpt:5353
ACCEPT     udp  --  0.0.0.0/0            0.0.0.0/0           udp dpt:631
ACCEPT     all  --  0.0.0.0/0            0.0.0.0/0           state RELATED,ESTABLISHED
ACCEPT     tcp  --  0.0.0.0/0            0.0.0.0/0           state NEW tcp dpt:22
ACCEPT     tcp  --  0.0.0.0/0            0.0.0.0/0           state NEW tcp dpt:80
ACCEPT     tcp  --  0.0.0.0/0            0.0.0.0/0           state NEW tcp dpt:21
ACCEPT     tcp  --  0.0.0.0/0            0.0.0.0/0           tcp dpt:25 state NEW
REJECT     all  --  0.0.0.0/0            0.0.0.0/0           reject-with icmp-host-prohibited
ACCEPT     tcp  --  0.0.0.0/0            0.0.0.0/0           tcp dpt:10000 state NEW
ACCEPT     tcp  --  0.0.0.0/0            0.0.0.0/0           tcp dpt:110 state NEW

Answer : Sendmail & POP via IPTABLES

Let me point something:

This is Wrong because you are rejecting every packet with icmp-host-prohibited, and therefore no packet can go any further:
-------------------
-A RH-Firewall-1-INPUT -j REJECT --reject-with icmp-host-prohibited
-A OUTPUT -p tcp -m tcp
-A RH-Firewall-1-INPUT -p tcp -m tcp -m state --dport 10000 --state NEW -j ACCEPT
-A RH-Firewall-1-INPUT -p tcp -m tcp -m state --dport 110 --state NEW -j ACCEPT
-------------------

So please try changing to this order:
-------------------
-A OUTPUT -p tcp -m tcp
-A RH-Firewall-1-INPUT -p tcp -m tcp -m state --dport 10000 --state NEW -j ACCEPT
-A RH-Firewall-1-INPUT -p tcp -m tcp -m state --dport 110 --state NEW -j ACCEPT
-A RH-Firewall-1-INPUT -j REJECT --reject-with icmp-host-prohibited
-------------------

and try again.