Can't connect to mail server from mail clients

Discussion in 'General' started by krogac, Feb 26, 2019.

  1. krogac

    krogac Member HowtoForge Supporter

    Hello,
    i just run my new ISP server and i can't connect to mo mail server from mail clients...
    Everything work ok from Roundcube.
    I use DNS from Cloudflare. All DNS names looks ok.
    ISP
     
  2. till

    till Super Moderator Staff Member ISPConfig Developer

  3. krogac

    krogac Member HowtoForge Supporter

    Hello, i have open all ports.
    Yesterday i change mail server. When i have this server in domain dev.example.com then everything works fine.
    I change DNS records, change domain names in ISP to work.example.com and now i have problems.
    I do not change firewall configurations.
    When i try connect by mail clients i get error:
    "Unable to connect to your IMAP server. You may have exceeded the maximum number of connections to this server. If so, use the Advanced IMAP Server Settings dialog to reduce the number cached connections."
     
  4. krogac

    krogac Member HowtoForge Supporter

    #### SERVER #####
    IP-address (as per hostname): ***.***.***.***
    [WARN] could not determine server's ip address by ifconfig
    [INFO] ISPConfig is installed.

    ##### ISPCONFIG #####
    ISPConfig version is 3.1.13


    ##### VERSION CHECK #####

    [INFO] php (cli) version is 7.0.33-0+deb9u1

    ##### PORT CHECK #####


    ##### MAIL SERVER CHECK #####


    ##### RUNNING SERVER PROCESSES #####

    [INFO] I found the following web server(s):
    Apache 2 (PID 519)
    [INFO] I found the following mail server(s):
    Unknown process (smtpd) (PID 634)
    [INFO] I found the following pop3 server(s):
    Dovecot (PID 859)
    [INFO] I found the following imap server(s):
    Dovecot (PID 859)
    [INFO] I found the following ftp server(s):
    PureFTP (PID 1426)

    ##### LISTENING PORTS #####
    (only ()
    Local (Address)
    [anywhere]:995 (859/dovecot)
    [localhost]:10023 (876/postgrey)
    [localhost]:10024 (769/amavisd-new)
    [localhost]:10025 (1193/master)
    [localhost]:10026 (769/amavisd-new)
    [localhost]:10027 (1193/master)
    [anywhere]:587 (1193/master)
    [localhost]:11211 (787/memcached)
    [anywhere]:110 (859/dovecot)
    [anywhere]:143 (859/dovecot)
    [anywhere]:465 (1193/master)
    [localhost]:9011 (775/php-fpm:)
    [anywhere]:21 (1426/pure-ftpd)
    ***.***.***.***:53 (774/named)
    [localhost]:53 (774/named)
    [anywhere]:22 (880/sshd)
    [anywhere]:25 (634/smtpd)
    [localhost]:953 (774/named)
    [anywhere]:993 (859/dovecot)
    *:*:*:*::*:995 (859/dovecot)
    *:*:*:*::*:10023 (876/postgrey)
    *:*:*:*::*:10024 (769/amavisd-new)
    *:*:*:*::*:10026 (769/amavisd-new)
    *:*:*:*::*:3306 (1004/mysqld)
    *:*:*:*::*:587 (1193/master)
    [localhost]10 (859/dovecot)
    [localhost]43 (859/dovecot)
    *:*:*:*::*:80 (519/apache2)
    *:*:*:*::*:8080 (519/apache2)
    *:*:*:*::*:465 (1193/master)
    *:*:*:*::*:8081 (519/apache2)
    *:*:*:*::*:21 (1426/pure-ftpd)
    *:*:*:*::*:53 (774/named)
    *:*:*:*::*:22 (880/sshd)
    *:*:*:*::*:25 (634/smtpd)
    *:*:*:*::*:953 (774/named)
    *:*:*:*::*:443 (519/apache2)
    *:*:*:*::*:993 (859/dovecot)




    ##### IPTABLES #####
    Chain INPUT (policy ACCEPT)
    target prot opt source destination
    f2b-postfix-sasl tcp -- [anywhere]/0 [anywhere]/0 multiport dports 25
    f2b-dovecot tcp -- [anywhere]/0 [anywhere]/0 multiport dports 110,995,143,993,587,465,4190
    f2b-pure-ftpd tcp -- [anywhere]/0 [anywhere]/0 multiport dports 21
    f2b-sshd tcp -- [anywhere]/0 [anywhere]/0 multiport dports 22

    Chain FORWARD (policy ACCEPT)
    target prot opt source destination

    Chain OUTPUT (policy ACCEPT)
    target prot opt source destination

    Chain f2b-dovecot (1 references)
    target prot opt source destination
    REJECT all -- ***.***.***.*** [anywhere]/0 reject-with icmp-port-unreachable
    RETURN all -- [anywhere]/0 [anywhere]/0

    Chain f2b-postfix-sasl (1 references)
    target prot opt source destination
    REJECT all -- ***.***.***.*** [anywhere]/0 reject-with icmp-port-unreachable
    REJECT all -- ***.***.***.*** [anywhere]/0 reject-with icmp-port-unreachable
    RETURN all -- [anywhere]/0 [anywhere]/0

    Chain f2b-pure-ftpd (1 references)
    target prot opt source destination
    RETURN all -- [anywhere]/0 [anywhere]/0

    Chain f2b-sshd (1 references)
    target prot opt source destination
    RETURN all -- [anywhere]/0 [anywhere]/0
     
  5. krogac

    krogac Member HowtoForge Supporter

    This is strange situation. Sometimes Mail Client ask for new certificate and get from server...
     
  6. till

    till Super Moderator Staff Member ISPConfig Developer

    The output above looks fine. DNS changes may take about 24 hours, so it might be that dns has not been fully changed yet in all dns caches. You might also want to check the dns zone at intodns.com, maybe you have a split brain situation where not all dns servers agree on the same data.
     
  7. krogac

    krogac Member HowtoForge Supporter

    I have a info from my server about Mailbox quota notification and i get info from mail... [email protected]....
    Not from my domain name.
     
  8. krogac

    krogac Member HowtoForge Supporter

    In monitor fail2ban send information 2019-02-27 08:47:40,456 fail2ban.actions [1039]: NOTICE [dovecot] Ban MY.IP.ADDRESS

    Ok, fail2ban block my ip address. Ugh :-D
     
    Last edited: Feb 27, 2019
  9. till

    till Super Moderator Staff Member ISPConfig Developer

    That's correct as the notification is sent from the server.
     
  10. krogac

    krogac Member HowtoForge Supporter

    Can i change this domain to my hostname?
     
  11. till

    till Super Moderator Staff Member ISPConfig Developer

    Run:

    grep server1.example.com /etc

    and change it in all files where it is found. Then change it in ispconfig under system > server services too.
     
  12. krogac

    krogac Member HowtoForge Supporter

    Ok, thanks!
     

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