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  1. Cloudron Forum
  2. Support
  3. No emails are being sent

No emails are being sent

Scheduled Pinned Locked Moved Solved Support
emaildns
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  • B Offline
    B Offline
    bnachbauer
    wrote on last edited by joseph
    #1

    Hello,

    I am running version 8.3.2 on Ubuntu 24.04.3. It is newly installed, but I restored a backup (same version) to change hosting providers (VM OVH -> other VM OVH).
    My problem is that no emails are being sent.
    In the logs, I have several types of messages:

    • Tried all MXs
    • DNS lookup failure: Error: queryMx ESERVFAIL

    On the forum, I found a similar case that allowed me to identify what I think is an anomaly:

    toto@cloudron:~$ host -t MX gmail.com 127.0.0.1
    ;; communications error to 127.0.0.1#53: connection refused
    ;; communications error to 127.0.0.1#53: connection refused
    ;; no servers could be reached
    toto@cloudron:~$ systemctl status unbound
    ● unbound.service - Unbound DNS Resolver
         Loaded: loaded (/etc/systemd/system/unbound.service; enabled; preset: enabled)
         Active: active (running) since Tue 2025-11-11 18:02:32 UTC; 14h ago
        Process: 9903 ExecStartPre=/usr/sbin/unbound-anchor -a /var/lib/unbound/root.key (code=exited, status=0/SUCCESS)
       Main PID: 10033 (unbound)
          Tasks: 1 (limit: 9434)
         Memory: 8.4M (peak: 8.8M)
            CPU: 342ms
         CGroup: /system.slice/unbound.service
                 └─10033 /usr/sbin/unbound -d
    
    Notice: journal has been rotated since unit was started, output may be incomplete.
    

    Do you have any idea what might be causing this problem and how to fix it?
    Thank you.

    J 1 Reply Last reply
    1
    • B Offline
      B Offline
      bnachbauer
      wrote on last edited by
      #2

      I just found a solution, but I'm not sure if it's very clean:

      • In /etc/unbound/unbound.conf.d/cloudron-network.conf, I:
        -- added interface: 127.0.0.1
        -- disabled IPv6: do-ip6: no
      • In OVH's Edge Firewall, I authorized all UDP
      1 Reply Last reply
      1
      • B bnachbauer

        Hello,

        I am running version 8.3.2 on Ubuntu 24.04.3. It is newly installed, but I restored a backup (same version) to change hosting providers (VM OVH -> other VM OVH).
        My problem is that no emails are being sent.
        In the logs, I have several types of messages:

        • Tried all MXs
        • DNS lookup failure: Error: queryMx ESERVFAIL

        On the forum, I found a similar case that allowed me to identify what I think is an anomaly:

        toto@cloudron:~$ host -t MX gmail.com 127.0.0.1
        ;; communications error to 127.0.0.1#53: connection refused
        ;; communications error to 127.0.0.1#53: connection refused
        ;; no servers could be reached
        toto@cloudron:~$ systemctl status unbound
        ● unbound.service - Unbound DNS Resolver
             Loaded: loaded (/etc/systemd/system/unbound.service; enabled; preset: enabled)
             Active: active (running) since Tue 2025-11-11 18:02:32 UTC; 14h ago
            Process: 9903 ExecStartPre=/usr/sbin/unbound-anchor -a /var/lib/unbound/root.key (code=exited, status=0/SUCCESS)
           Main PID: 10033 (unbound)
              Tasks: 1 (limit: 9434)
             Memory: 8.4M (peak: 8.8M)
                CPU: 342ms
             CGroup: /system.slice/unbound.service
                     └─10033 /usr/sbin/unbound -d
        
        Notice: journal has been rotated since unit was started, output may be incomplete.
        

        Do you have any idea what might be causing this problem and how to fix it?
        Thank you.

        J Online
        J Online
        joseph
        Staff
        wrote on last edited by
        #3

        @bnachbauer For DNS,

        127.0.0.53 - systemd-resolved of default ubuntu runs here
        127.0.0.150 - cloudron's internal DNS (unbound) runs here. this is also used by mail server.

        There is nothing running on 127.0.0.1 out of the box. The forum post you saw are obsolete. I think what fixed it was opening the UDP firewall required for DNS to go out. I think you can remove the interface: 127.0.0.1 line.

        1 Reply Last reply
        0
        • J joseph has marked this topic as solved on
        • B Offline
          B Offline
          bnachbauer
          wrote on last edited by
          #4

          I confirm. It work without 127.0.0.1

          1 Reply Last reply
          1

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