Do you use a reverse proxy or is the cow is alone in the meadow?

    Hmm, updated to latest version? nginx running, no errors?

      heavygale yes i can connect to the ui and under /debug everything is green

        Maybe it’s a IPv6 vs IPv4 issue? Do both A and AAAA Records point to your server and do both work?

        i dont use IPv6 and i did not change anything. also the url is working from random computers. so dns settings should be correct.

        Found the problem.
        in the mailcow.conf was localhost set as ip for port 80 for port 443 it was correct.

        changed it now its working.

          MrYoshii I don’t understand the fix, waht in detail have you done? Since a few days i get also the same issue like it was written above. Please help me out.

              AudiWolf MrYoshii I don’t understand the fix, what in detail have you done? Since a few days I get also the following issue. Before everything was working fine. Please help me out.
              10.08.2022, 23:41:12 mail.domain.tld - Use SKIP_LETS_ENCRYPT=y in mailcow.conf to skip it permanently.
              10.08.2022, 23:41:12 mail.domain.tld - Cannot validate any hostnames, skipping Let's Encrypt for 1 hour.
              10.08.2022, 23:41:12 mail.domain.tld - Cannot match your IP 0000:0000:0000:0000:0000:0000:0000:0000 against hostname mail.domain.tld (DNS returned XXXX:YYYY:XXXX:YYYY:0000:0000:0000:0001)
              10.08.2022, 23:41:12 mail.domain.tld - Found AAAA record for mail.domain.tld: 2a01:4f8:1c1e:d0ba::1 - skipping A record check
              10.08.2022, 23:41:12 mail.domain.tld - Cannot match your IP 0000:0000:0000:0000:0000:0000:0000:0000 against hostname autoconfig.domain.tld (DNS returned XXXX:YYYY:XXXX:YYYY:0000:0000:0000:0001)
              10.08.2022, 23:41:12 mail.domain.tld - Found AAAA record for autoconfig.domain.tld: 2a01:4f8:1c1e:d0ba::1 - skipping A record check
              10.08.2022, 23:41:12 mail.domain.tld - Cannot match your IP 0000:0000:0000:0000:0000:0000:0000:0000 against hostname autodiscover.domain.tld (DNS returned XXXX:YYYY:XXXX:YYYY:0000:0000:0000:0001)
              10.08.2022, 23:41:12 mail.domain.tld - Found AAAA record for autodiscover.domain.tld: 2a01:4f8:1c1e:d0ba::1 - skipping A record check
              10.08.2022, 23:41:12 mail.domain.tld - Cannot match your IP 0000:0000:0000:0000:0000:0000:0000:0000 against hostname mta-sts.domain.tld (DNS returned XXXX:YYYY:XXXX:YYYY:0000:0000:0000:0001)
              10.08.2022, 23:41:12 mail.domain.tld - Found AAAA record for mta-sts.domain.tld: 2a01:4f8:1c1e:d0ba::1 - skipping A record check
              10.08.2022, 23:41:12 mail.domain.tld - Cannot match your IP 0000:0000:0000:0000:0000:0000:0000:0000 against hostname autoconfig.domain.tld (DNS returned XXXX:YYYY:XXXX:YYYY:0000:0000:0000:0001)
              10.08.2022, 23:41:11 mail.domain.tld - Found AAAA record for autoconfig.domain.tld: 2a01:4f8:1c1e:d0ba::1 - skipping A record check
              10.08.2022, 23:41:11 mail.domain.tld - Cannot match your IP 0000:0000:0000:0000:0000:0000:0000:0000 against hostname autodiscover.domain.tld (DNS returned XXXX:YYYY:XXXX:YYYY:0000:0000:0000:0001)
              10.08.2022, 23:41:11 mail.domain.tld - Found AAAA record for autodiscover.domain.tld: 2a01:4f8:1c1e:d0ba::1 - skipping A record check
              10.08.2022, 23:41:11 mail.domain.tld - Cannot match your IP 0000:0000:0000:0000:0000:0000:0000:0000 against hostname mta-sts.domain.tld (DNS returned XXXX:YYYY:XXXX:YYYY:0000:0000:0000:0001)
              10.08.2022, 23:41:11 mail.domain.tld - Found AAAA record for mta-sts.domain.tld: 2a01:4f8:1c1e:d0ba::1 - skipping A record check
              10.08.2022, 23:41:11 mail.domain.tld - OK: abc.def.efg.hij, 0000:0000:0000:0000:0000:0000:0000:0000
              10.08.2022, 23:40:32 mail.domain.tld - Detecting IP addresses...
              10.08.2022, 23:40:32 mail.domain.tld - Using existing Lets Encrypt account key /var/lib/acme/acme/account.pem
              10.08.2022, 23:40:32 mail.domain.tld - Using existing domain rsa key /var/lib/acme/acme/key.pem
              10.08.2022, 23:40:32 mail.domain.tld - Initializing, please wait...
              10.08.2022, 23:40:32 mail.domain.tld - OK

                  AudiWolf hi in the mailcow.conf
                  for me it was like this:

                  HTTP_PORT=80
HTTP_BIND=127.0.0.1

HTTPS_PORT=443
HTTPS_BIND=144.76.60.71

                  and after i changed it to:

                  HTTP_PORT=80
HTTP_BIND=144.76.60.71

HTTPS_PORT=443
HTTPS_BIND=144.76.60.71

                  and after a restart it did work again.

                      MrYoshii Thanks for the quick answer. In my case this doesn’t help. Anyy other ideas?

                          AudiWolf you can try to set SKIP_IP_CHECK=y in the config. Your error is"Cannot match your IP 0000:0000:0000:0000:0000:0000:0000:0000 against hostname mta-sts.domain.tld (DNS returned XXXX:YYYY:XXXX:YYYY:0000:0000:0000:0001)" Or maybe your dns settings are not correct.

                              a year later

                              Hi,
                              just saw your post.
                              Helped me a lot.
                              Couldn’t renew Cert.
                              After i read the answers, i tried to disable ipv6. and it worked for me.
                              Just follow step 1. here :
                              docs.mailcow.email Icon Disable IPv6 - mailcow: dockerized documentation

                              docs.mailcow.email Icon docs.mailcow.email
                              Disable IPv6 - mailcow: dockerized documentation
                              None
                              docs.mailcow.email

                              then
                              docker compose down
                              docker compose up -d

                              Finally the cert was created new with a few errors on ipv6.
                              After that i just did the same and activated ipv6 again.
                              And now the whole process worked fine.

                              I know it is a old post, but maybe someone else finds this post and can also solve there problem.

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