iptables blocking some requests on ports 80 and 25 - linux

Question

I have this iptables rules:
# iptables -n -L -v --line-numbers
Chain INPUT (policy DROP 0 packets, 0 bytes)
num pkts bytes target prot opt in out source destination
1 7392 4841K ACCEPT all -- lo * 0.0.0.0/0 0.0.0.0/0
2 250K 531M ACCEPT all -- * * 0.0.0.0/0 0.0.0.0/0 state RELATED,ESTABLISHED
3 0 0 ACCEPT all -- * * 192.168.0.0/24 0.0.0.0/0
4 0 0 ACCEPT all -- * * 80.1.1.69 0.0.0.0/0
5 6929 360K ACCEPT all -- * * 110.50.200.145 0.0.0.0/0
6 23 1404 ACCEPT all -- * * 100.40.30.0/24 0.0.0.0/0
7 781 46428 ACCEPT tcp -- * * 0.0.0.0/0 0.0.0.0/0 tcp dpt:22 state NEW,ESTABLISHED
8 101 5928 ACCEPT tcp -- * * 0.0.0.0/0 0.0.0.0/0 tcp dpt:25 state NEW,ESTABLISHED
9 5664 338K ACCEPT tcp -- * * 0.0.0.0/0 0.0.0.0/0 tcp dpt:80 state NEW,ESTABLISHED
10 846 65748 LOGGING all -- * * 0.0.0.0/0 0.0.0.0/0
11 0 0 REJECT all -- * * 0.0.0.0/0 0.0.0.0/0 reject-with icmp-host-prohibited
Chain FORWARD (policy DROP 0 packets, 0 bytes)
num pkts bytes target prot opt in out source destination
1 0 0 REJECT all -- * * 0.0.0.0/0 0.0.0.0/0 reject-with icmp-host-prohibited
Chain OUTPUT (policy ACCEPT 147K packets, 381M bytes)
num pkts bytes target prot opt in out source destination
Chain LOGGING (1 references)
num pkts bytes target prot opt in out source destination
1 734 46882 LOG all -- * * 0.0.0.0/0 0.0.0.0/0 limit: avg 6/min burst 5 LOG flags 0 level 7 prefix `iptables: '
2 846 65748 DROP all -- * * 0.0.0.0/0 0.0.0.0/0
The thing is the log file shows lines like these:
Jan 28 17:31:30 myhostname kernel: iptables: IN=eth0 OUT= MAC=78:24:ff:3a:3b:0e:00:09:0f:09:3b:06:08:00 SRC=188.85.58.233 DST=210.6.60.254 LEN=40 TOS=0x00 PREC=0x00 TTL=54 ID=40229 DF PROTO=TCP SPT=56131 DPT=80 WINDOW=0 RES=0x00 RST URGP=0
Jan 21 22:54:03 myhostname kernel: iptables: IN=eth0 OUT= MAC=78:24:af:3a:3b:0c:00:09:0f:09:3b:06:08:00 SRC=217.12.26.61 DST=210.6.60.254 LEN=40 TOS=0x00 PREC=0x00 TTL=41 ID=0 DF PROTO=TCP SPT=35401 DPT=25 WINDOW=0 RES=0x00 RST URGP=0
Note that, I have port 80 and 25 open.
Why some connection get block by iptables on 80 and 25?. I steel get trafic to those two services, but I dont understand why ip tables block some of the conections.
Thank you

Answer 1

You will note at the end of those log lines, the packets have the tcp reset flag set:
...WINDOW=0 RES=0x00RSTURGP=0
Probably, conntrack thinks that the connection is not in a state where this is a sensible packet to receive, and conntrack will mark them as INVALID. This means that they are not picked up by rule #2. They also do not count as NEW or ESTABLISHED when your rules #7-9 in your chain are hit.
Hence, they hit your log rule #10 and are rejected by rule #11.
You can either ignore this, or add a rule somewhere before your log line to deal with INVALID packets:
-m conntrack --ctstate INVALID -j DROP