Firewall is blocking packets for hMailServer

I installed hMailServer on a Windows 7 (SP1) machine for mail delivery only inside a local network.

After configuring a pair of mailboxes, I also configured a Thunderbird client in the same machine and it worked, being able to both send and receive mails.

A Thunderbird client in another machine (in the same LAN) does not work instead. I even tried to completely disable the Windows Firewall, but the problem is the same. If I try to telnet the <windows_7_IP> I obtain

$ telnet <windows_7_IP> 25
Trying <windows_7_IP>...
Connected to <windows_7_IP>.
Escape character is '^]'.
Connection closed by foreign host.

also, nmap provides

PORT     STATE SERVICE     VERSION 
25/tcp   open  tcpwrapped
|_smtp-commands: Couldn't establish connection on port 25 
110/tcp  open  tcpwrapped 
143/tcp  open  tcpwrapped

even after stopping and restarting the hMailServer service.

With the Windows Firewall turned off, but logging turned on, the firewall log records were:

#Version: 1.5
#Software: Microsoft Windows Firewall
#Time Format: Local
#Fields: date time action protocol src-ip dst-ip src-port dst-port size tcpflags tcpsyn tcpack tcpwin icmptype icmpcode info path

<date> <time> DROP TCP <client_IP> <windows_7_IP> 62041 49154 44 S 3502231060 0 1024 - - - RECEIVE
<date> <time> DROP TCP <client_IP> <windows_7_IP> 62042 49154 44 S 3502165525 0 1024 - - - RECEIVE
<date> <time> DROP TCP <client_IP> <windows_7_IP> 62043 49154 44 S 3502099990 0 1024 - - - RECEIVE
<date> <time> DROP TCP <client_IP> <windows_7_IP> 62041 49156 44 S 3502231060 0 1024 - - - RECEIVE
<date> <time> DROP TCP <client_IP> <windows_7_IP> 62042 49156 44 S 3502165525 0 1024 - - - RECEIVE
<date> <time> DROP TCP <client_IP> <windows_7_IP> 62043 49156 44 S 3502099990 0 1024 - - - RECEIVE

during the telnet and nmap connections.

What else could be done in order to make the Windows 7 machine accessible to mail clients?

BowPark

Posted 2014-12-09T17:44:00.123

Reputation: 195

If I am diagnosing a potential issue with the Windows 7 Firewall, I have almost never had to look at firewall logs or rely on trying a big server like hmailserver or some client program.. I go in cygwin and do nc -l 123 or nc -l -p 123 and get it listening on that port and nc 127.0.0.1 123 (nc is like telnet there) see if the firewall is stopping it. Nevertheless, you could do it with hmailserver and your thunderbird client.. – barlop – 2014-12-09T18:42:00.240

Try telnet 127.0.0.1 25 see if that works. Try from another computer in your LAN telnet 192.168.1.3 25 And if you think your firewall is an issue then you have to look at the rules in your firewall for inbound connections. I just read you say you even tried disabling the firewall and you still have the problem. Why on earth are you saying(in your title even too), that it's your firewall blocking it if you said you disabled the firewall and it's still not working? I guess you think you can't turn the firewall off – barlop – 2014-12-09T18:43:16.000

Firewall is blocking packets for hMailServer

No answers