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@esackbauer

Could you tell me where exactly are the dkim keys in mailcow stored? Files or database? And I’d like to know how to get there.

More testing with emails to a vodafone account:

mx5.vodafonemail.de/4SV90B37Vyz9ryY;
dkim=fail reason=“signature verification failed” (2048-bit key; unprotected) header.d=x.de header.i=@x.de header.a=rsa-sha256 header.s=dkim header.b=cVJitv3G;
dkim-atps=neutral

I did a diff -s file1 <– dkim from mailcow file2 <– dkim copied to DNS. They are identical.

Could it be, that if restoring a mailcow backup, the keys are messed up? I’d like to check the keys (public and private) before restore and after restore.

    stefan21 Could it be, that if restoring a mailcow backup, the keys are messed up?

    That could be. Probably they are stored in the Redis DB. I remember a thread in this forum where they discussed problems with the DKIM keys.

      Well, I’d like to check this. What’s the best approach to access the DB?

      BTW here’s the email to the vodafone account:

      "
      test
      –=20
      Mit freundlichen Gr=C3=BC=C3=9Fen,

      Mit freundlichen Gr=C3=BC=C3=9Fen,

      =C3=B6=C3=A4=C3=BC=C3=9F

      "

      Umlaute in signature and domain footer… as already seen. Of course with a failed dkim key after a restore. To verify the suspicion I’ll wipe/delete the mailcow install on my laptop and start over with a new, clean install. No restores, no imports, nothing. Means from scratch. Will report.

        stefan21
        Now I am thinking that the Umlaute conversion is the reason why the DKIM fails. Something is changing the character encoding in transit and changing the “checksum”. Maybe the DKIM keys are fine.

        I never tried to access the Redis DB, don’t know.

            esackbauer Now I am thinking that the Umlaute conversion is the reason why the DKIM fails. Something is changing the character encoding in transit and changing the “checksum”.

            Let me start over with a fresh clean install. I’ll create a domain (same I use for tests), a user, will copy the new dkim key to DNS, nothing more. I’ll do a “vanilla” backup. First email will be with no umlaute. Second email will have umlaute. Third email will have signature and Umlaute. Forth one will have the signature and a system wide footer with umlaute.

            I’ll report.

              I did the tests. Here are the results:

              1. Sending an email from SOGO in HTML format, no matter what language, with signature and footer, with german umlaute, works correct. The dkim test pass:
                mx5.vodafonemail.de/4SVGtc1n9xz9rxk;
                dkim=pass (2048-bit key; unprotected) header.d=y.de header.i=@y.de header.a=rsa-sha256 header.s=dkim header.b=An7pjvp1;
                dkim-atps=neutral

              2. Sending an email from SOGO in plain text format, no matter what language, with signature and footer, with german umlaute, will not work. The dkim test fails.
                mx5.vodafonemail.de/4SVH2f6TNFz6vhw;
                dkim=fail reason=“signature verification failed” (2048-bit key; unprotected) header.d=y.de header.i=@y.de header.a=rsa-sha256 header.s=dkim header.b=QWmUDGNz;
                dkim-atps=neutral

              Reverting in SOGO back to html text will pass the dkim test (again).

              1. Sending an email form email-client thunderbird in HTML format, no matter what language, with signature and footer, with german umlaute, will not work. dkim test fails. The layout of the email looks like:
                "
                umlaute: =C3=B6=C3=A4=C3=BC=C3=9F

              –=20
              Mit freundlichen Gr=C3=BC=C3=9Fen,

              1. Sending emails from thunderbird will always fail the dkim test. No matter if plain text or html.

              To resume:

              • sending emails from SOGO in html containing german umlaute, works. DKIM will pass.
              • sending emails from SOGO in plain text containing german umlaute leads to DKIM fails.
              • sending emails from email-client thunderbird will always fail the dkim test. And the german umlaute are in a wrong format.

              As we need thunderbird out of several reasons, at this moment with the results above, I cannot migrate my email servers to mailcow. We send, and will this probably do also in future, emails only in plain text format. And we need dkim, dmarc and spf - valid.

              Besides the question of restoring a backup to different box with another underlying OS and the decryption of the emails, while doing a restore of all items including the keys. But this point for the moment is less important, it could be solved in another way.

              How to proceed?

              Can’t tell. Sending emails composed in sogo with plain text and umlaute to i.e. domain hosted at allinkl brings up the same result:

              Authentication-Results: q.kasserver.com;
              dkim=fail reason=“signature verification failed” (2048-bit key; unprotected) header.d=x.de header.i=@x.de header.a=rsa-sha256 header.s=dkim header.b=JevnIlCW;
              dkim-atps=neutral

              I’m sending from a socalled pool IP: IP-x.x.x.x-um38.pools.vodafone-ip.de. Means not a static IP. But if this causes the failure, then the failure should also be while sending in HTML. As I pointed out, DKIM passes with email sent from the same (dynamic) IP(4).

              IMVHO I don’t think so.

                stefan21 OK, according to your header examples from above it was always mx5.vodafonemail.de which had the problem with your DKIM, so I thought it’s Vodafone specific.
                But, as I wrote above, no DKIM problems here sending plaintext mails with Sogo

                  @DocFraggle

                  If you like, you could tell me one of your email adresses (is in this forum a pm function?). I’ll send you an email. Let’s see how this works.

                  Well, since yesterday I have one user who also has encoding troubles. User is on iPad with ActiveSync configured. User can send via SOGo without problems, but from Apples integrated mail client outgoing mails are totally unreadable.
                  Had no time to investigate further yet.

                    esackbauer OK, I just checked this on my iPad and my ActiveSync account, works as usual with iPadOS 16.7.2 and after updating to iPadOS 17.1.1 in my case

                      Have deleted and reinstalled the Activesync account with my Ipad user. Problem persists. But only with that iPad user.
                      Installed the mobileconfig IMAP profile and everything as back to normal.

                      DocFraggle
                      @esackbauer

                      Here’s the result from the dkimvalidator:

                      #######
                      Original Message:

                      Received: from mail.z.de (ip-109-192-q-q.um38.pools.vodafone-ip.de [109.192.q.q])
                      by relay-1.us-west-2.relay-prod (Postfix) with ESMTPS id BB5E628E53
                      for RO3ER2LYBB7X5n@dkimvalidator.com; Fri, 17 Nov 2023 11:44:00 +0000 (UTC)
                      Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost (Mailerdaemon) with ESMTPA id 203793C009C
                      for RO3ER2LYBB7X5n@dkimvalidator.com; Fri, 17 Nov 2023 12:43:54 +0100 (CET)
                      DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=z.de; s=dkim;
                      t=1700221435;
                      h=from:reply-to:subject:date:message-id:to:mime-version:content-type:
                      content-transfer-encoding; bh=lZj4ZrwRyEiLyclvgIilptURN6KHsH85iH83mFdpfT0=;
                      b=WOezYpMCyhYml9qghfu2Iikoe9pM7Rbdk1G3L0aTEsLcknLE13xr2kza07cc6y+/cQTBDz
                      vLwzHs2pUqdohgDrFvuvUnGzKa8SD/3rLDDImyor37oWIYCe2f/GTjr6H18Gfq3mzOc/wq
                      Fd45OF0rbl/ACT7bmNfpWFOuBLyIpdhadysT6ggYT+dSaXYrFDTnCGC/Ux4tYaD+Uuy/r2
                      A09tU6tqTNFCk3OKc6QdelA1D5663ZQI9y58nF1v8MZ2BCl1MgtaPdaEmPQKFsjNeR9plG
                      GBokcfLamSFqHDajTTphfw4QGAWMC4RavRs508MPfd5Hl0YFhjobYFZ7xbsLug==
                      From: “X Y” x.y@z.de
                      Content-Type: text/plain; charset=“utf-8”
                      Reply-To: x.y@z.de
                      Date: Fri, 17 Nov 2023 12:43:54 +0100
                      To: RO3ER2LYBB7X5n@dkimvalidator.com
                      MIME-Version: 1.0
                      Message-ID: <42-65575200-3-560d3d80@48021463>
                      Subject: =?utf-8?q?T=C3=84SCHT?=
                      User-Agent: SOGoMail 5.9.0
                      Content-Transfer-Encoding: quoted-printable
                      X-Last-TLS-Session-Version: None

                      Sogo, plain text, signatur mit umlauten, footer mit umlauten

                      –=20
                      signature

                      plain text
                      =C3=B6=C3=A4=C3=BC=C3=9F

                      plain footer
                      =C3=B6=C3=A4=C3=BC=C3=9F

                      #######
                      DKIM Information:

                      DKIM Signature

                      Message contains this DKIM Signature:
                      DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=z.de; s=dkim;
                      t=1700221435;
                      h=from:reply-to:subject:date:message-id:to:mime-version:content-type:
                      content-transfer-encoding; bh=lZj4ZrwRyEiLyclvgIilptURN6KHsH85iH83mFdpfT0=;
                      b=WOezYpMCyhYml9qghfu2Iikoe9pM7Rbdk1G3L0aTEsLcknLE13xr2kza07cc6y+/cQTBDz
                      vLwzHs2pUqdohgDrFvuvUnGzKa8SD/3rLDDImyor37oWIYCe2f/GTjr6H18Gfq3mzOc/wq
                      Fd45OF0rbl/ACT7bmNfpWFOuBLyIpdhadysT6ggYT+dSaXYrFDTnCGC/Ux4tYaD+Uuy/r2
                      A09tU6tqTNFCk3OKc6QdelA1D5663ZQI9y58nF1v8MZ2BCl1MgtaPdaEmPQKFsjNeR9plG
                      GBokcfLamSFqHDajTTphfw4QGAWMC4RavRs508MPfd5Hl0YFhjobYFZ7xbsLug==

                      Signature Information:
                      v= Version: 1
                      a= Algorithm: rsa-sha256
                      c= Method: relaxed/relaxed
                      d= Domain: z.de
                      s= Selector: dkim
                      q= Protocol:
                      bh= lZj4ZrwRyEiLyclvgIilptURN6KHsH85iH83mFdpfT0=
                      h= Signed Headers: from:reply-to:subject:date:message-id:to:mime-version:content-type:
                      content-transfer-encoding
                      b= Data: WOezYpMCyhYml9qghfu2Iikoe9pM7Rbdk1G3L0aTEsLcknLE13xr2kza07cc6y+/cQTBDz
                      vLwzHs2pUqdohgDrFvuvUnGzKa8SD/3rLDDImyor37oWIYCe2f/GTjr6H18Gfq3mzOc/wq
                      Fd45OF0rbl/ACT7bmNfpWFOuBLyIpdhadysT6ggYT+dSaXYrFDTnCGC/Ux4tYaD+Uuy/r2
                      A09tU6tqTNFCk3OKc6QdelA1D5663ZQI9y58nF1v8MZ2BCl1MgtaPdaEmPQKFsjNeR9plG
                      GBokcfLamSFqHDajTTphfw4QGAWMC4RavRs508MPfd5Hl0YFhjobYFZ7xbsLug==
                      Public Key DNS Lookup

                      Building DNS Query for dkim._domainkey.z.de
                      Retrieved this publickey from DNS: v=DKIM1;k=rsa;t=s;s=email;p=MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAtHkJ1zfpaCrbEr5y4riJc82jyNtNheQrREUuH1dhKOwfhyIeqHtAWPir5sdkn418FJ8j4Zu1N7g0xqQqvceXwllO2xik+tLAsWMYk2t7XvD7IWM9D1awaC9QgTPXk7v9mGEjh1HSvrxyBr7Fa8cJP56Ujhda7xpCw05AZTJL7Nu3hgnc6dEAotF1qEIpof6XJ5XW0zzd3cxvyN5TE12ewSYE6GblgtQjTNYyGaW2l4o8Kxpw6Qha1XowoDq/Eyv2PFyPbUg8i3QXLxBaGJQ0U+j8Tk0T1iay1AukZAdCvnPa8UCrc9CkKQ73TG+nd9OL4zZdwSVWWYTV8MzjwgABowIDAQAB
                      Validating Signature

                      result = fail
                      Details: message has been altered

                      #######
                      SPF Information:

                      Using this information that I obtained from the headers

                      Helo Address = mail.z.de
                      From Address = x.x@z.de
                      From IP = 109.192.q.q
                      SPF Record Lookup

                      Looking up TXT SPF record for z.de
                      Found the following namesevers for z.de: ns5.kasserver.com ns6.kasserver.com
                      Retrieved this SPF Record: zone updated 20210630 (TTL = 167)
                      using authoritative server (ns5.kasserver.com) directly for SPF Check
                      Result: pass (Mechanism ‘mx’ matched)

                      Result code: pass
                      Local Explanation: z.de: 109.192.q.q is authorized to use ‘x.y@z.de’ in ‘mfrom’ identity (mechanism ‘mx’ matched)
                      spf_header = Received-SPF: pass (z.de: 109.192.q.q is authorized to use ‘x.y@z.de’ in ‘mfrom’ identity (mechanism ‘mx’ matched)) receiver=ip-172-31-52-154.ec2.internal; identity=mailfrom; envelope-from=“x.y@z.de”; helo=mail.z.de; client-ip=109.192.q.q

                      Same test, but as html text in sogo:

                      #######
                      From: “x y” x.y@z.de
                      Content-Type: multipart/alternative; boundary=“—-==-OpenGroupware_org_NGMime-65-1700222345.461701-0——”
                      Reply-To: x.y@z.de
                      Date: Fri, 17 Nov 2023 12:59:05 +0100
                      To: iBsUWO3nrKugbZ@dkimvalidator.com
                      MIME-Version: 1.0
                      Message-ID: <41-65575580-5-677bcc00@203231989>
                      Subject: =?utf-8?q?T=C3=84SCHT?=
                      User-Agent: SOGoMail 5.9.0
                      X-Last-TLS-Session-Version: None

                      ——==-OpenGroupware_org_NGMime-65-1700222345.461701-0——
                      Content-Type: text/plain; charset=utf-8
                      Content-Transfer-Encoding: quoted-printable

                      Sogo, html text, signatur mit umlauten, footer mit umlauten

                      –=C2=A0
                      signature plain text =C3=B6=C3=A4=C3=BC=C3=9F

                      plain footer
                      =C3=B6=C3=A4=C3=BC=C3=9F

                      ——==-OpenGroupware_org_NGMime-65-1700222345.461701-0——
                      Content-Type: text/html; charset=utf-8
                      Content-Transfer-Encoding: quoted-printable

                      <html>Sogo, html text, signatur mit umlauten, footer mit umlauten<br /><br />–=
                      &nbsp;<br />signature plain text =C3=B6=C3=A4=C3=BC=C3=9F</html>

                      html footer
                      =C3=B6=C3=A4=C3=BC=C3=9F

                      ——==-OpenGroupware_org_NGMime-65-1700222345.461701-0——–

                      #######
                      Public Key DNS Lookup

                      Building DNS Query for dkim._domainkey.z.de
                      Retrieved this publickey from DNS: v=DKIM1;k=rsa;t=s;s=email;p=MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAtHkJ1zfpaCrbEr5y4riJc82jyNtNheQrREUuH1dhKOwfhyIeqHtAWPir5sdkn418FJ8j4Zu1N7g0xqQqvceXwllO2xik+tLAsWMYk2t7XvD7IWM9D1awaC9QgTPXk7v9mGEjh1HSvrxyBr7Fa8cJP56Ujhda7xpCw05AZTJL7Nu3hgnc6dEAotF1qEIpof6XJ5XW0zzd3cxvyN5TE12ewSYE6GblgtQjTNYyGaW2l4o8Kxpw6Qha1XowoDq/Eyv2PFyPbUg8i3QXLxBaGJQ0U+j8Tk0T1iay1AukZAdCvnPa8UCrc9CkKQ73TG+nd9OL4zZdwSVWWYTV8MzjwgABowIDAQAB
                      Validating Signature

                      result = pass
                      Details:

                      But - bad format with umlaute.

                      Anyway - we need as email-client thunderbird.

                      As I already wrote, if it helps I have other linux mailservers in my LAN(s) (also with sogo, not used), I can provide configs and versions. The used programs are AFAIK pretty much the same.

                      If there’s interest to track this down, I’d suggest to do this not in this forum. It’s better done via email.

                        Details: message has been altered

                        Strange, is there anything in-between your mailcow and your local gateway to the internet?
                        The validator had no problems on my side with plain text Umlaut mails from Sogo…

                          DocFraggle trange, is there anything in-between your mailcow and your local gateway to the internet

                          That is also my suspicion. Some transparent filters on the firewall I would guess.

                            O.k. thank’s for sharing your thoughts.

                            I’ll check/disable in case anything on my asus home router, and will test again. I’ll be back.

                            I disabled diversion and skynet, the router DNS is unbound.

                            DKIM passes, encoding/format is faulty:

                            Date: Fri, 17 Nov 2023 14:32:31 +0100
                            To: djrEXr4DjZ2CAP@dkimvalidator.com
                            MIME-Version: 1.0
                            Message-ID: <41-65576b80-d-677bcc00@203232121>
                            Subject: =?utf-8?q?T=C3=84SCHT?=
                            User-Agent: SOGoMail 5.9.0
                            X-Last-TLS-Session-Version: None

                            ——==-OpenGroupware_org_NGMime-65-1700227951.204159-2——
                            Content-Type: text/plain; charset=utf-8
                            Content-Transfer-Encoding: quoted-printable

                            sogo html text, signatur and footer mit umlaute
                            =C3=A4=C3=B6=C3=BC=C3=9F

                            –=C2=A0
                            signature plain text =C3=B6=C3=A4=C3=BC=C3=9F

                            plain footer
                            =C3=B6=C3=A4=C3=BC=C3=9F

                            ——==-OpenGroupware_org_NGMime-65-1700227951.204159-2——
                            Content-Type: text/html; charset=utf-8
                            Content-Transfer-Encoding: quoted-printable

                            <html>sogo html text, signatur and footer mit umlaute<br />=C3=A4=C3=B6=C3=BC=
                            =C3=9F<br /><br />–&nbsp;<br />signature plain text =C3=B6=C3=A4=C3=BC=C3=9F</=
                            html>

                            html footer
                            =C3=B6=C3=A4=C3=BC=C3=9F

                            ——==-OpenGroupware_org_NGMime-65-1700227951.204159-2——–

                            What is this ——==-OpenGroupware_org_NGMime-65-1700227951.204159-2——– about?

                            From the postfix log, sent with TB, no matter same result with SOGo:

                            B0AD2427BCA: replace: header Received: from cdc97c45df2b (mailcowdockerized-sogo-mailcow-1.mailcowdockerized_mailcow-network [172.22.1.248])??(Authenticated sender: x.y@z.de)??by mail.z.de (Postcow) with ESMTP from mailcowdockerized-sogo-mailcow-1.mailcowdockerized_mailcow-network[172.22.1.248]; from=x.y@z.de to=check-auth@verifier.port25.com proto=ESMTP helo=<cdc97c45df2b>: Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost (Mailerdaemon) with ESMTPA id B0AD2427BCA??for check-auth@verifier.port25.com; Sat, 18 Nov 2023 01:54:47 +0100 (CET)

                            The header, the body and the DKIM key is corrupted. No idea what replace: header received means…

                            DNS-Check in mailcow says everything is fine.

                            Mailcow is running on top of archlinux. Laptop is WLAN connected. Static IP is 192.168.XX.YYY. Gateway is the router (for test every possible interference disabled), tried DMZ, portforwarding, etc. There’s no reverse proxy running on the laptop. No firewall, no filters on the laptop. Something must be wrong on the way from the container via docker to the router.

                            As I already mentioned, I’m running a few other mailservers NOT DOCKERIZED, nearly the same configuration (postfix, dovecot, fail2ban, rspamd, sogo (same ver.).

                            I have to give up. At this very moment I cannot use mailcow in production environment. I’m sorry.

                            Ok… one more thing came to my mind while reading your last post: from the debug outputs you posted and the .de domains I guess you are German? Did you setup your Archlinux in German as well? If so, maybe it’s some kind of encoding issue with the German locale? I haven’t had a look yet if the locale of the host system is used while setting up the docker containers of mailcow in the first place, but maybe… My host system is running with en_us.UTF-8

                            You guess right, I’m German.

                            Here’s the info:

                            #$ localectl
                            System Locale: LANG=C.UTF-8
                            VC Keymap: de
                            X11 Layout: de

                            To my mind another possible issue came across. As I have a pool IP from vodafone (cable), this is not a static IP, it might be impossible to setup a mailserver without having a static IP4. They charge you extra if you want a static one.

                            Is there a workaround possible with i.e. DDNS and cname in DNS? Don’t know, never tried this. There was no reason for this…

                              stefan21 it might be impossible to setup a mailserver without having a static IP4.

                              That is true. It is working for receiving mails, but no chance to send mails via a dynamic IP.
                              Pay for a relay service then (they can read your mails…), or get a business cable product with static IP and the possibility to have a reverse DNS entry, or pay for a decent hoster.

                                  I´m sending mail from a dynamic IP, no mail´s get rejected so it´s possible.
                                  Before that i used smtp2go, also work´s great.

                                    storpotaten no mail´s get rejected so it´s possible.

                                    With a relay service yes. Otherwise you are very very lucky.

                                      Maybe, my IP resolves to “94-255-167-***.cust.bredband2.com” the host of my ISP,
                                      i could be wrong but if everhing else in in place DKIM, SPF and so on the sending of emails seems to work.
                                      i´m far from an emailserver expert but this is my experience.

                                        esackbauer That is true. It is working for receiving mails, but no chance to send mails via a dynamic IP.
                                        Pay for a relay service then (they can read your mails…), or get a business cable product with static IP and the possibility to have a reverse DNS entry, or pay for a decent hoster.

                                        In business we have only static IP’s. Not for private. Question is, could a dynamic IP have an impact on DKIM? Hmm…?

                                        Anyone out there running mailcow on top of any linux OS with a dynamic IP?

                                          storpotaten
                                          Some servers might still decline your mail because it’s on a DNSBL for dial up/dynamic IPs.
                                          I know because I am in the same situation 🙂
                                          This is why I use a relay.

                                            storpotaten I´m sending mail from a dynamic IP, no mail´s get rejected so it´s possible.

                                            Thank’s for jumping on.

                                            AFAIK any email sent from a dynamic IP would be rejected from my customers and suppliers. In business a dynamic IP is no option. It’ll simply won’t work.

                                            [unknown]

                                            If you’re using a relay, this is not what I’m looking for. We don’t send email through a relay. We are running our email servers totally on our own. No relay, no smarthost, no connector, … I mean, what for? We are talking about an email server. No need for anything around. That’s it.

                                                stefan21 If you’re using a relay, this is not what I’m looking for. We don’t send email through a relay. We are running our email servers totally on our own. No relay, no smarthost, no connector, … I mean, what for? We are talking about an email server. No need for anything around. That’s it.

                                                Sure, it’s “just” an email server, but most of the mails sent by it will be rejected nonetheless due to you dynamic IP, wether it’s private or for business purposes. Looking up the IP blacklist is a default option not only for mailcow.
                                                And it’s a real pain if you never can be sure if your mail has been delivered or just silently dropped by the SPAM filter…
                                                Just saying 😃

                                                  Maybe I didn’t make it clear enough: in business we do only use static IP’s and email-servers without relay, smarthost, … All business domains have 10/10 at mail-tester. No issues at all, no matter where or what I test against.

                                                  Not so for private. As I said, the vodafone IP is so-called pool-IP, not static.

                                                  Follow up while digging around:

                                                  1. I had to change my fritzbox 6490 cable in bridge mode. Exposed host for the asus router behind was not enough.
                                                  2. Now the asus shows a WAN IP, which in (real) bridge mode of the fritzbox is a different one as shown in the fritzbox. The WAN IP shown in the asus is to be set in the DNS settings at the hoster.
                                                  3. The laptop is configured as DMZ in the asus.
                                                  4. On the laptop I installed nginx as reversed proxy. I took the example config from mailcow and changed it to my domain.
                                                  5. I started over with a new mailcow-docker installation.
                                                  6. Unbound container was unhealthy. As the asus is running with unbound, I tried to point the forward zone in unbound.conf to the IP of the asus. That didn’t work. Unbound container showed healthy, but error during the acme challenge occurred. I changed the IP to 1.1.1.1. That worked. The challenge completed.
                                                  7. I created a domain and a test user.
                                                  8. I took the dkim key to the DNS (as well as the other settings to make).
                                                  9. I tested from sogo an email to email-tester composed in html. So far o.k., dkim passes, not a 10/10 because auf rDNS setting. This was to expect.
                                                  10. Changed sogo to plain text, email test also o.k.
                                                  11. Tried thunderbird - email tests also o.k.
                                                  12. Did a backup.

                                                  Well - it is was not so easy to track this down. Still some questions open. But maybe it helps someone. I’ll keep this running and testing at home for a while. If the mailcow runs smooth, I’ll migrate my email servers in business. And will donate for this great work.

                                                  regards,
                                                  stefan

                                                    10 months later

                                                    stefan21

                                                    Hey,

                                                    also have the same Fritz!Box (Vodafone) here, but couldn’t get the bridge-mode working.
                                                    Maybe you got a tip?

                                                    Thanks.

                                                      I don’t have a customized FritzBox. It’s an original. Therefore I can’t help. You should ask Vodafone.

                                                        6 days later

                                                        Vodafone is my provider. At home I don’t have a static IP. Therefore I use an unbranded (no customized firmware) fritzbox.

                                                        Read this: ubiquiti - Deutsches Fan Forum Icon Fritz!Box | Cable (6490, 6590, 6591, 6660) Bridge-Mode freischalten - ubiquiti - Deutsches Fan Forum

                                                        ubiquiti - Deutsches Fan Forum Icon ubiquiti - Deutsches Fan Forum
                                                        Fritz!Box | Cable (6490, 6590, 6591, 6660) Bridge-Mode freischalten - ubiquiti - Deutsches Fan Forum

                                                        And this: mengelke.de Icon Fritz!Box JSTool

                                                        mengelke.de Icon mengelke.de
                                                        Fritz!Box JSTool
                                                        Checksum mit JavaScript berechnen, Konfig-Datei entschl
                                                        MEngelke.demengelke.dezu HTTPS wechseln

                                                        This adds the option “bridged mode” to an unbranded fritzbox.

                                                        In business we use Vodafone only with static IP’s. This allows to run their customized fritzbox firmware in bridged mode.

                                                        If all pre-requisites are fulfilled (read mailcow docs) the mailserver works flawless.

                                                        @sOliver

                                                        Even with this hack you’ll have an IP from their pool. It’s not a dedicated static IP which only belongs to you. You’ll definitely have problems sending emails. Check the blacklists… A mailserver without a static dedicated IP is not recommended.

                                                          a month later
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