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13 Replies Latest reply: Oct 12, 2012 4:11 PM by alan.pae RSS

Sendmail

S2801 Newbie
Currently Being Moderated
Hi,

I'm having problems with sendmail on a solaris server. It seems the messages are just getting queued up and not being sent from the system. All other servers in the domain are configured the same way and they don't seem to be having problems sending emails. It's just this one particular server. It is running Solaris 10.

When I run sendmail -v user.name@domain < /dev/null - it sends the message to the mail queue, and eventually I see the message deferred: connection timed out to <mailserver>

When I try to telnet to the mail server on port 25 I see the following:

Connected to hostname.domain
Escape character is '^]'.
Connection to hostname.domain closed by foreign host.

I don't know a lot about sendmail, and would really appreciate some help with this.

Thanks.
  • 1. Re: Sendmail
    alan.pae Journeyer
    Currently Being Moderated
    When I try to telnet to the mail server on port 25 I see the following:

    Connected to hostname.domain
    Escape character is '^]'.
    Connection to hostname.domain closed by foreign host.
    What happens when you try this from a working machine. Do any firewall rules either on the machine or somewhere else block it.

    alan
  • 2. Re: Sendmail
    S2801 Newbie
    Currently Being Moderated
    Alan,

    Thanks for replying.

    When I try the telnet from a working machine, a connection is established and I am able to send an email to myself successfully. I can also run the sendmail -v command successfully. Emails are sent through ok.
  • 3. Re: Sendmail
    alan.pae Journeyer
    Currently Being Moderated
    Ok, so you may have "netservices limited" set on this one sever. So, send an email message to a user on the same server. Then send a message to a user on a different server on your side of the firewall. Or just use telnet again. If it goes through then your being blocked somewhere on your side.

    alan
  • 4. Re: Sendmail
    S2801 Newbie
    Currently Being Moderated
    Hi,

    If I send an email to a user on the same server, it seems that is sent through. If I try to send an email to a user on a different server on the same subnet, it seems to hang when it gets to the point below:

    MAIL FROM: user1@servername
    RCPT TO: user2@servername
    DATA
    Enter mail, end with "." on a line by itself
    .



    Also, I cannot telnet to the smtp server on port 25

    # telnet <smtpserver> 25
    Trying 172.30.6.17...
    Connected to <smtpserver.domain>
    Escape character is '^]'.
    Connection to <smtpserver.domain> closed by foreign host.

    I'm not sure what "netservices limited" means?

    Hope this makes sense.

    Thanks.
  • 5. Re: Sendmail
    alan.pae Journeyer
    Currently Being Moderated
    Yea, it does sound like this server has netservices limited set. To change it use netservices open instead.
    <pre>man netservices </pre>
    for details and check with your company's main admin to make sure that is should be set to open instead of limited.

    alan
  • 6. Re: Sendmail
    S2801 Newbie
    Currently Being Moderated
    Thanks, I will find out what it should be set to. Will see if that makes any difference.
  • 7. Re: Sendmail
    S2801 Newbie
    Currently Being Moderated
    This was a network issue. A network port going to a switch had been unplugged due to fault on the switch. So, traffic was only passing through one network port and switch instead of the two switches. Now the fault on switch has been resolved and port was plugged back into the switch, it seems email is working ok now. Traffic is going through ok. Will monitor it over the next few days.

    Thanks
  • 8. Re: Sendmail
    S2801 Newbie
    Currently Being Moderated
    After monitoring it for a few days, the problem has re-emerged. It's the same issue where mails are being queued up and not sending. HELP!

    Any help is very much appreciated.
  • 9. Re: Sendmail
    ML Starkey-Oracle Journeyer
    Currently Being Moderated
    Hopefully, you checked that it's not the same network switch port issue again?
    Perhaps your switch admin is setting up VLANs or access restrictions there?
    Are other network communications to a system on the same subnet as the mail server working?
    How about to other network ports i.e telnet, ssh, rlogin, etc.?
    /EXACT/ same symptoms as last time with respect to connecting directly to the mail server on port 25?

    no real ideas, just brainstorming.
  • 10. Re: Sendmail
    S2801 Newbie
    Currently Being Moderated
    No there haven't been any vlan restrictions configured.
    Other servers on the same subnet have mail working.
    Other ports on the problematic server are ok. i.e ssh is working fine.
    The exact same problem.

    What happens now is, the server can telnet to the mail server on port 25 sometimes, and other times I seem to get a connection closed by foreign host.

    Thanks.
  • 11. Re: Sendmail
    ML Starkey-Oracle Journeyer
    Currently Being Moderated
    Is the mail server a Solaris machine? If so, or even if it is not, there should be a syslog
    or /var/adm/messages to check and see if there is anything interesting being recorded.

    I assume those other servers on the same subnet are connecting to the same
    problematic outbound mail server?

    It may be time to break out "snoop", Wireshark or your favorite network trace tool.
    Ideally, you will be able to snoop/trace both sides on port 25 and reproduce the failure.
  • 12. Re: Sendmail
    836014 Journeyer
    Currently Being Moderated
    Do you have a mail server in the environment thru the mail are routing? Would be able to ping or resolve the mailserver host/IP using nslookup?

    Check what is defined in your resolv.conf and /etc/hosts.
  • 13. Re: Sendmail
    alan.pae Journeyer
    Currently Being Moderated
    Odds are good no one here can help you.

    You seem to be having some sort of network issue. You can try another switch port, swap cables, whatever. But until you have a guaranteed nailed up connection we can't help. Take to your networking folks and have them assist. It might even be a flaky network port on the Sun box but you need to troubleshoot the intermittent network disconnects.

    alan

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