No incoming mails!

Discussion in 'Installation/Configuration' started by mlanglois, Jan 22, 2006.

  1. mlanglois

    mlanglois New Member

    I've installed a server with ISPConfig. It's just GREAT!
    Everything seems to be working well, except for incoming mails from outside.
    I may be wrong, but I think the problem comes from the fact that port 25 is closed from outside.
    I mean, on the server side it is open: I checked with netstat, and if I do telnet localhost 25 it works. I also checked the ISPConfig firewall to make sure port 25 is open. But if I try telnet from outside, it doesn't work.
    If I send emails to users from an outside account, they finally come back with a "Connection timed out" error. If think this is normal if indeed port 25 is closed. Am I wrong?
    If I'm right, the next question is: why is port 25 closed? How can I open it?

    BTW, I should also mention that I'm not using any port-forwarding (as I would do with my router at home) because the server is hosted in my university with its own public IP.

    Please, anyone has a suggestion? Anything I should check?
     
  2. falko

    falko Super Moderator Howtoforge Staff

    What's the value of inet_interfaces in /etc/postfix/main.cf?
    Please post the output of
    Code:
    iptables -L
    Can you make sure your university isn't blocking port 25?
     
  3. mlanglois

    mlanglois New Member

    Here it is:
    Code:
    inet_interfaces = all
    --> So far so good...

    Here it is:
    Code:
    Chain INPUT (policy DROP)
    target     prot opt source               destination
    DROP       tcp  --  anywhere             loopback/8
    ACCEPT     all  --  anywhere             anywhere            state RELATED,ESTABLISHED
    ACCEPT     all  --  anywhere             anywhere
    DROP       all  --  BASE-ADDRESS.MCAST.NET/4  anywhere
    PUB_IN     all  --  anywhere             anywhere
    PUB_IN     all  --  anywhere             anywhere
    PUB_IN     all  --  anywhere             anywhere
    DROP       all  --  anywhere             anywhere
    
    Chain FORWARD (policy DROP)
    target     prot opt source               destination
    ACCEPT     all  --  anywhere             anywhere            state RELATED,ESTABLISHED
    DROP       all  --  anywhere             anywhere
    
    Chain INT_IN (0 references)
    target     prot opt source               destination
    ACCEPT     icmp --  anywhere             anywhere
    DROP       all  --  anywhere             anywhere
    
    Chain INT_OUT (0 references)
    target     prot opt source               destination
    ACCEPT     icmp --  anywhere             anywhere
    ACCEPT     all  --  anywhere             anywhere
    
    Chain OUTPUT (policy ACCEPT)
    target     prot opt source               destination
    PUB_OUT    all  --  anywhere             anywhere
    PUB_OUT    all  --  anywhere             anywhere
    PUB_OUT    all  --  anywhere             anywhere
    
    Chain PAROLE (11 references)
    target     prot opt source               destination
    ACCEPT     all  --  anywhere             anywhere
    
    Chain PUB_IN (3 references)
    target     prot opt source               destination
    ACCEPT     icmp --  anywhere             anywhere            icmp destination-unreachable
    ACCEPT     icmp --  anywhere             anywhere            icmp echo-reply
    ACCEPT     icmp --  anywhere             anywhere            icmp time-exceeded
    ACCEPT     icmp --  anywhere             anywhere            icmp echo-request
    PAROLE     tcp  --  anywhere             anywhere            tcp dpt:ftp
    PAROLE     tcp  --  anywhere             anywhere            tcp dpt:ssh
    PAROLE     tcp  --  anywhere             anywhere            tcp dpt:smtp
    PAROLE     tcp  --  anywhere             anywhere            tcp dpt:domain
    PAROLE     tcp  --  anywhere             anywhere            tcp dpt:http
    PAROLE     tcp  --  anywhere             anywhere            tcp dpt:hosts2-ns
    PAROLE     tcp  --  anywhere             anywhere            tcp dpt:pop3
    PAROLE     tcp  --  anywhere             anywhere            tcp dpt:https
    PAROLE     tcp  --  anywhere             anywhere            tcp dpt:ndmp
    PAROLE     tcp  --  anywhere             anywhere            tcp dpt:imap
    PAROLE     tcp  --  anywhere             anywhere            tcp dpt:imaps
    ACCEPT     udp  --  anywhere             anywhere            udp dpt:domain
    DROP       icmp --  anywhere             anywhere
    DROP       all  --  anywhere             anywhere
    
    Chain PUB_OUT (3 references)
    target     prot opt source               destination
    ACCEPT     all  --  anywhere             anywhere
    --> Anything wrong with it?

    --> If no other explanation can be found, that might the reason. I would have to ask...
     
  4. falko

    falko Super Moderator Howtoforge Staff

    That would be good because the things you posted look ok.
     
  5. mlanglois

    mlanglois New Member

    Well, I had confirmation that port 25 is indeed blocked by the university! :mad:

    I've been told that such port blocking is more and more common, so if other users experience the same problem, check with your network administrator or ISP if they're not doing the same!

    Thank you for your help falko! ;)
     

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