Email server not working to external (host rejected)

[Mykael]

If I try to telnet port 25 on your server, it's not responding...

Are you sure port 25 is open? I tried using the domain you posted here. That's an issue.

M B

I flushed all configs from iptables, added again new rules, installed Nmap to check if tcp/udp ports are opened.
here are the result:

Starting Nmap 5.51 ( http://nmap.org ) at 2016-05-01 11:13 EEST
Nmap scan report for mail.rocomputers.ro (193.138.195.25)
Host is up (0.000094s latency).
PORT    STATE  SERVICE
25/udp  closed smtp
53/udp  open   domain
80/udp  closed http
465/udp closed smtps
All 1000 scanned ports on mail.rocomputers.ro (193.138.195.25) are open|filtered

I can see now that something is wrong in the udp ports, but seems that even if i set the rules to allow them, they are ignored and remain closed.
------------------------------
Another scan for TCP ports:
Starting Nmap 5.51 ( http://nmap.org ) at 2016-05-01 11:53 EEST
Nmap scan report for mail.rocomputers.ro (193.138.195.25)
Host is up (0.000015s latency).
Not shown: 10006 closed ports
PORT     STATE SERVICE
21/tcp   open  ftp
22/tcp   open  ssh
25/tcp   open  smtp
53/tcp   open  domain
80/tcp   open  http
110/tcp  open  pop3
143/tcp  open  imap
587/tcp  open  submission
3306/tcp open  mysql
4190/tcp open  sieve

My current iptables rules are this:

# Generated by iptables-save v1.4.7 on Sun May  1 10:52:50 2016
*filter
:INPUT DROP [3:1728]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [9:3096]
-A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
-A INPUT -p tcp -m tcp --tcp-flags FIN,SYN,RST,PSH,ACK,URG NONE -j DROP
-A INPUT -p tcp -m tcp ! --tcp-flags FIN,SYN,RST,ACK SYN -m state --state NEW -j DROP
-A INPUT -p tcp -m tcp --tcp-flags FIN,SYN,RST,PSH,ACK,URG FIN,SYN,RST,PSH,ACK,URG -j DROP
-A INPUT -i lo -j ACCEPT
-A INPUT -s 89.40.29.186/32 -p tcp -m tcp --dport 22 -j ACCEPT
-A INPUT -s 193.138.195.25/32 -p tcp -m tcp --dport 22 -j ACCEPT
-A INPUT -p udp -m state --state NEW -m udp --dport 53 -j ACCEPT
-A INPUT -p udp -m state --state NEW -m udp --dport 80 -j ACCEPT
-A INPUT -p udp -m state --state NEW -m udp --dport 465 -j ACCEPT
-A INPUT -p tcp -m tcp --dport 20 -j ACCEPT
-A INPUT -p tcp -m tcp --dport 21 -j ACCEPT
-A INPUT -p tcp -m tcp --dport 22 -j ACCEPT
-A INPUT -p tcp -m tcp --dport 25 -j ACCEPT
-A INPUT -p tcp -m tcp --dport 53 -j ACCEPT
-A INPUT -p tcp -m tcp --dport 80 -j ACCEPT
-A INPUT -p tcp -m tcp --dport 110 -j ACCEPT
-A INPUT -p tcp -m tcp --dport 143 -j ACCEPT
-A INPUT -p tcp -m tcp --dport 443 -j ACCEPT
-A INPUT -p tcp -m tcp --dport 465 -j ACCEPT
-A INPUT -p tcp -m tcp --dport 587 -j ACCEPT
-A INPUT -p tcp -m tcp --dport 3306 -j ACCEPT
-A INPUT -p tcp -m tcp --dport 995 -j ACCEPT
-A INPUT -p tcp -m tcp --dport 10025 -j ACCEPT
COMMIT
# Completed on Sun May  1 10:52:50 2016
--------------------------------------------

Tested the iptables chain policy:
Chain INPUT (policy DROP)
target     prot opt source               destination
ACCEPT     all  --  anywhere             anywhere            state RELATED,ESTABLISHED
DROP       tcp  --  anywhere             anywhere            tcp flags:FIN,SYN,RST,PSH,ACK,URG/NONE
DROP       tcp  --  anywhere             anywhere            tcp flags:!FIN,SYN,RST,ACK/SYN state NEW
DROP       tcp  --  anywhere             anywhere            tcp flags:FIN,SYN,RST,PSH,ACK,URG/FIN,SYN,RST,PSH,ACK,URG
ACCEPT     all  --  anywhere             anywhere
ACCEPT     tcp  --  186.29.40.89.abcnet.ro  anywhere            tcp dptsh
ACCEPT     tcp  --  mail.rocomputers.ro  anywhere            tcp dptsh
ACCEPT     udp  --  anywhere             anywhere            state NEW udp dpt:domain
ACCEPT     udp  --  anywhere             anywhere            state NEW udp dpt:http
ACCEPT     udp  --  anywhere             anywhere            state NEW udp dpt:igmpv3lite
ACCEPT     tcp  --  anywhere             anywhere            tcp dpt:ftp-data
ACCEPT     tcp  --  anywhere             anywhere            tcp dpt:ftp
ACCEPT     tcp  --  anywhere             anywhere            tcp dptsh
ACCEPT     tcp  --  anywhere             anywhere            tcp dptmtp
ACCEPT     tcp  --  anywhere             anywhere            tcp dpt:domain
ACCEPT     tcp  --  anywhere             anywhere            tcp dpt:http
ACCEPT     tcp  --  anywhere             anywhere            tcp dpt:pop3
ACCEPT     tcp  --  anywhere             anywhere            tcp dpt:imap
ACCEPT     tcp  --  anywhere             anywhere            tcp dpt:https
ACCEPT     tcp  --  anywhere             anywhere            tcp dpt:urd
ACCEPT     tcp  --  anywhere             anywhere            tcp dptubmission
ACCEPT     tcp  --  anywhere             anywhere            tcp dpt:mysql
ACCEPT     tcp  --  anywhere             anywhere            tcp dpt:pop3s
ACCEPT     tcp  --  anywhere             anywhere            tcp dpt:10025

Chain FORWARD (policy ACCEPT)
target     prot opt source               destination

Chain OUTPUT (policy ACCEPT)
target     prot opt source               destination

I test also in telnet, and it gives me the ESMT mesage that i added in configs, and nothing else..
Can i get a working iptables with corect rules (il add manually for test)? if you have..., or tell me if something is wrong with them, pls.

Im still newbie to linux, i come from zpanel from windows, but i'm learning fast the new operating system.