design: server-dmarc-hint - the server's own name gets a DMARC record

Owner, 2026-10-18: "Оба предложения делаем" (the roadmap's
server-dmarc-hint, from the security audit's S3). Settings › Notification
mail gets a third record after DKIM and SPF: DMARC at _dmarc.<hostname>,
value v=DMARC1; p=reject, with a help line - without it a receiver does
not refuse mail forged in the server's name, a false password-reset
message included; only the panel sends as this name, signed, so reject is
safe. Health's Notification mail card gets the DMARC row; Help's
Notifications topic names all three records. check.py: 0 violations;
outlines.json rewritten for the third record of the Settings box
(record×2 -> record×3).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

docs/assets/panel-redesign/panel/health.html

@@ -158,6 +158,7 @@
             <tbody>
               <tr><td>DKIM<br><span class="sp-muted sp-mono sp-small">sp2026._domainkey.mail.example.org</span></td><td><span class="tag is-success is-light">published</span></td></tr>
               <tr><td>SPF<br><span class="sp-muted sp-mono sp-small">mail.example.org</span></td><td><span class="tag is-warning is-light">missing</span></td></tr>
+              <tr><td>DMARC<br><span class="sp-muted sp-mono sp-small">_dmarc.mail.example.org</span></td><td><span class="tag is-warning is-light">missing</span></td></tr>
             </tbody>
           </table></div>
           <div class="sp-box-body">

docs/assets/panel-redesign/panel/help.html

@@ -147,7 +147,7 @@
           <div class="sp-help-topic" id="backup"><h3>Backup and moving a domain</h3><p>Full backup downloads one archive of the whole instance: <code>data/</code> (the database, DKIM keys and application credentials), <code>docker-compose.yml</code>, <code>.env</code> and <code>certs/</code>. Both it and a domain's export ask for your account password - the one you sign in with - at every download, so a session left open is not enough to take them; a wrong one counts against the limit of a password change, ten in 15 minutes. The Postfix queue is not in it. The backup is taken while the server is running, and Postfix keeps moving messages through the queue, so a copy could hold a message twice or miss it; mail still waiting for delivery is therefore not carried over, and a restored server starts with an empty queue. To keep the queue, stop the container and archive the project directory instead. The private key in <code>certs/</code> has to be readable by the panel: give it to group 10997 on the host (<code>chgrp 10997</code>, <code>chmod 640</code>), a group only the panel is in, so Postfix's daemons cannot read it. Until then the panel refuses to make a backup and names the file, rather than hand over an archive without the key. It holds secrets, so leave Encrypt with a password ticked: the file is sealed as <code>.spbk</code>, the password is not stored, and without it nothing can be recovered. To restore, unpack it into an empty project directory (decrypt a <code>.spbk</code> first with <code>selfpost-backup -decrypt</code>) and start the same SelfPost version that made it; the panel refuses data from another version. The reverse-proxy configuration and <code>mail.log</code> are not included. One domain moves on its own: Export domain on its settings page writes a <code>.json</code> (or encrypted <code>.spde</code>) with its DKIM key and its applications' passwords, and Import a domain here reads it into another instance, so the published DNS needs no change.</p></div>
           <div class="sp-help-topic" id="users"><h3>Users and roles</h3><p>The two roles are a reach, not a rank: every user is an administrator and signs in with a username and password. Global reaches the whole server — Overview, Server, the queue and every domain — and is the only role that adds or deletes domains and users. Domain reaches only the domains assigned to it, outbound and inbound separately (the same name on both lists is two assignments); <em>All</em> includes domains added later, and a domain user needs at least one domain or <em>All</em> on either list. The only global user cannot be demoted or deleted, and you cannot delete the account you are signed in with. A new password set here signs that user out everywhere; set for yourself, it keeps the session you set it from. Adding a user, changing a user's password, e-mail or role, and deleting a user ask for your own account password, as a backup does, with the same limit on wrong guesses.</p></div>
           <div class="sp-help-topic" id="settings"><h3>Settings</h3><p>Settings holds what is true of the whole instance. The time zone is the container's, <code>TZ</code> in <code>.env</code> (UTC when it is not set): every time the panel shows and every day it counts is that zone's, as are the stamps Postfix writes in <code>mail.log</code>, so the two always agree; changing it is a restart of the container. The one exception is the day a DMARC report covers, which is the reporter's, counted in UTC. Log retention is how many days the Outbound log keeps its rows, from 7 to 365 and 90 by default; a sweep every six hours deletes older ones, and it is the main driver of how fast <code>/data</code> grows. With the inbound relay on there is a second number, for the Inbound log, with the same range. It does not change the rotation of <code>mail.log</code>, which is daily with about two weeks kept. The sending rate limit shown under it is level 1, the per-client-IP ceiling set in <code>.env</code>: changing it needs a restart, and no level-2 limit can exceed it. Notifications are turned on or off here for everyone.</p></div>
-          <div class="sp-help-topic" id="notifications"><h3>Notifications</h3><p>The panel writes to its users when something needs them, from <code>postmaster@</code> the server's hostname. Four things are reported. A sending domain's SPF, DKIM or DMARC record stops matching: sent once two hourly checks in a row have found it so, and once more when the record matches again. A level-2 rate limit refuses mail: sent at the first refusal, then at most once a day for the same sending domain. The TLS certificate is 14 days from expiry, and again at 3 days if it is still the same certificate. A message has waited in the queue for more than three days, with one more message when none is left. A global user is told all of it; a domain administrator is told about the DNS records and limits of their own domains.<br><br>Each user turns notifications on or off under Account and needs an e-mail there; Server › Settings turns them off for everyone. They are the panel's own mail: not rows of the Outbound log, and not counted against any limit.<br><br>For that mail to arrive, the server's own name needs two DNS records of its own, as each of your domains does: a DKIM key, which the panel generates and signs notifications with, and an SPF record, <code>v=spf1 a -all</code>. Server › Settings gives both with the values to publish and whether they are in place, and its Re-check DNS checks them again once they are published; Server › Health shows them too. Without them notifications are still sent, and a receiver may file them as spam. Mail of your domains does not depend on either.</p></div>
+          <div class="sp-help-topic" id="notifications"><h3>Notifications</h3><p>The panel writes to its users when something needs them, from <code>postmaster@</code> the server's hostname. Four things are reported. A sending domain's SPF, DKIM or DMARC record stops matching: sent once two hourly checks in a row have found it so, and once more when the record matches again. A level-2 rate limit refuses mail: sent at the first refusal, then at most once a day for the same sending domain. The TLS certificate is 14 days from expiry, and again at 3 days if it is still the same certificate. A message has waited in the queue for more than three days, with one more message when none is left. A global user is told all of it; a domain administrator is told about the DNS records and limits of their own domains.<br><br>Each user turns notifications on or off under Account and needs an e-mail there; Server › Settings turns them off for everyone. They are the panel's own mail: not rows of the Outbound log, and not counted against any limit.<br><br>For that mail to arrive, the server's own name needs DNS records of its own, as each of your domains does: a DKIM key, which the panel generates and signs notifications with, an SPF record, <code>v=spf1 a -all</code>, and a DMARC record, <code>v=DMARC1; p=reject</code>, which has receivers refuse mail forged in the server's name - a false password-reset message among it; only the panel sends as this name, signed, so reject is safe. Server › Settings gives all three with the values to publish and whether they are in place, and its Re-check DNS checks them again once they are published; Server › Health shows them too. Without them notifications are still sent, and a receiver may file them as spam. Mail of your domains depends on none of them.</p></div>
         </div>
         <div class="box">
           <div class="sp-box-head"><span class="sp-no">05</span><h2>Account</h2></div>

docs/assets/panel-redesign/panel/outlines.json

@@ -402,7 +402,7 @@
     },
     {
      "is-6": [
-      "box[Notification mail]:record×2",
+      "box[Notification mail]:record×3",
       "box[Sending rate limits]:body",
       "box[Time zone]:body"
      ]

docs/assets/panel-redesign/panel/settings.html

@@ -128,6 +128,18 @@
               <div class="field has-addons"><div class="control is-expanded"><input class="input" readonly value="v=spf1 a -all"></div><div class="control"><button type="button" class="button"><i class="ti ti-copy"></i>Copy</button></div></div></div>
             <p class="help">Notifications are sent without it, and a receiver may file them as spam.</p>
           </div>
+
+          <div class="sp-record">
+            <div class="sp-record-head"><h3>DMARC</h3><span class="tag is-warning is-light">missing</span><small>For the server's own name, not for your domains</small></div>
+            <div class="sp-row">
+              <div class="field"><label class="label">Host / name</label>
+                <div class="field has-addons"><div class="control is-expanded"><input class="input" readonly value="_dmarc.mail.example.org"></div><div class="control"><button type="button" class="button"><i class="ti ti-copy"></i>Copy</button></div></div></div>
+              <div class="field"><label class="label">Type</label><div class="control"><input class="input" readonly value="TXT"></div></div>
+            </div>
+            <div class="field"><label class="label">Value to publish</label>
+              <div class="field has-addons"><div class="control is-expanded"><input class="input" readonly value="v=DMARC1; p=reject"></div><div class="control"><button type="button" class="button"><i class="ti ti-copy"></i>Copy</button></div></div></div>
+            <p class="help">Without it a receiver does not refuse mail forged in the server's name - a false password-reset message included. Only the panel sends as this name, signed, so reject is safe.</p>
+          </div>
         </div>
 
         <div class="box" id="rate-limits">

docs/assets/panel-redesign/panel/src/health.html

@@ -92,6 +92,7 @@
             <tbody>
               <tr><td>DKIM<br><span class="sp-muted sp-mono sp-small">sp2026._domainkey.mail.example.org</span></td><td><span class="tag is-success is-light">published</span></td></tr>
               <tr><td>SPF<br><span class="sp-muted sp-mono sp-small">mail.example.org</span></td><td><span class="tag is-warning is-light">missing</span></td></tr>
+              <tr><td>DMARC<br><span class="sp-muted sp-mono sp-small">_dmarc.mail.example.org</span></td><td><span class="tag is-warning is-light">missing</span></td></tr>
             </tbody>
           </table></div>
           <div class="sp-box-body">

docs/assets/panel-redesign/panel/src/help.html

@@ -81,7 +81,7 @@
           <div class="sp-help-topic" id="backup"><h3>Backup and moving a domain</h3><p>Full backup downloads one archive of the whole instance: <code>data/</code> (the database, DKIM keys and application credentials), <code>docker-compose.yml</code>, <code>.env</code> and <code>certs/</code>. Both it and a domain's export ask for your account password - the one you sign in with - at every download, so a session left open is not enough to take them; a wrong one counts against the limit of a password change, ten in 15 minutes. The Postfix queue is not in it. The backup is taken while the server is running, and Postfix keeps moving messages through the queue, so a copy could hold a message twice or miss it; mail still waiting for delivery is therefore not carried over, and a restored server starts with an empty queue. To keep the queue, stop the container and archive the project directory instead. The private key in <code>certs/</code> has to be readable by the panel: give it to group 10997 on the host (<code>chgrp 10997</code>, <code>chmod 640</code>), a group only the panel is in, so Postfix's daemons cannot read it. Until then the panel refuses to make a backup and names the file, rather than hand over an archive without the key. It holds secrets, so leave Encrypt with a password ticked: the file is sealed as <code>.spbk</code>, the password is not stored, and without it nothing can be recovered. To restore, unpack it into an empty project directory (decrypt a <code>.spbk</code> first with <code>selfpost-backup -decrypt</code>) and start the same SelfPost version that made it; the panel refuses data from another version. The reverse-proxy configuration and <code>mail.log</code> are not included. One domain moves on its own: Export domain on its settings page writes a <code>.json</code> (or encrypted <code>.spde</code>) with its DKIM key and its applications' passwords, and Import a domain here reads it into another instance, so the published DNS needs no change.</p></div>
           <div class="sp-help-topic" id="users"><h3>Users and roles</h3><p>The two roles are a reach, not a rank: every user is an administrator and signs in with a username and password. Global reaches the whole server — Overview, Server, the queue and every domain — and is the only role that adds or deletes domains and users. Domain reaches only the domains assigned to it, outbound and inbound separately (the same name on both lists is two assignments); <em>All</em> includes domains added later, and a domain user needs at least one domain or <em>All</em> on either list. The only global user cannot be demoted or deleted, and you cannot delete the account you are signed in with. A new password set here signs that user out everywhere; set for yourself, it keeps the session you set it from. Adding a user, changing a user's password, e-mail or role, and deleting a user ask for your own account password, as a backup does, with the same limit on wrong guesses.</p></div>
           <div class="sp-help-topic" id="settings"><h3>Settings</h3><p>Settings holds what is true of the whole instance. The time zone is the container's, <code>TZ</code> in <code>.env</code> (UTC when it is not set): every time the panel shows and every day it counts is that zone's, as are the stamps Postfix writes in <code>mail.log</code>, so the two always agree; changing it is a restart of the container. The one exception is the day a DMARC report covers, which is the reporter's, counted in UTC. Log retention is how many days the Outbound log keeps its rows, from 7 to 365 and 90 by default; a sweep every six hours deletes older ones, and it is the main driver of how fast <code>/data</code> grows. With the inbound relay on there is a second number, for the Inbound log, with the same range. It does not change the rotation of <code>mail.log</code>, which is daily with about two weeks kept. The sending rate limit shown under it is level 1, the per-client-IP ceiling set in <code>.env</code>: changing it needs a restart, and no level-2 limit can exceed it. Notifications are turned on or off here for everyone.</p></div>
-          <div class="sp-help-topic" id="notifications"><h3>Notifications</h3><p>The panel writes to its users when something needs them, from <code>postmaster@</code> the server's hostname. Four things are reported. A sending domain's SPF, DKIM or DMARC record stops matching: sent once two hourly checks in a row have found it so, and once more when the record matches again. A level-2 rate limit refuses mail: sent at the first refusal, then at most once a day for the same sending domain. The TLS certificate is 14 days from expiry, and again at 3 days if it is still the same certificate. A message has waited in the queue for more than three days, with one more message when none is left. A global user is told all of it; a domain administrator is told about the DNS records and limits of their own domains.<br><br>Each user turns notifications on or off under Account and needs an e-mail there; Server › Settings turns them off for everyone. They are the panel's own mail: not rows of the Outbound log, and not counted against any limit.<br><br>For that mail to arrive, the server's own name needs two DNS records of its own, as each of your domains does: a DKIM key, which the panel generates and signs notifications with, and an SPF record, <code>v=spf1 a -all</code>. Server › Settings gives both with the values to publish and whether they are in place, and its Re-check DNS checks them again once they are published; Server › Health shows them too. Without them notifications are still sent, and a receiver may file them as spam. Mail of your domains does not depend on either.</p></div>
+          <div class="sp-help-topic" id="notifications"><h3>Notifications</h3><p>The panel writes to its users when something needs them, from <code>postmaster@</code> the server's hostname. Four things are reported. A sending domain's SPF, DKIM or DMARC record stops matching: sent once two hourly checks in a row have found it so, and once more when the record matches again. A level-2 rate limit refuses mail: sent at the first refusal, then at most once a day for the same sending domain. The TLS certificate is 14 days from expiry, and again at 3 days if it is still the same certificate. A message has waited in the queue for more than three days, with one more message when none is left. A global user is told all of it; a domain administrator is told about the DNS records and limits of their own domains.<br><br>Each user turns notifications on or off under Account and needs an e-mail there; Server › Settings turns them off for everyone. They are the panel's own mail: not rows of the Outbound log, and not counted against any limit.<br><br>For that mail to arrive, the server's own name needs DNS records of its own, as each of your domains does: a DKIM key, which the panel generates and signs notifications with, an SPF record, <code>v=spf1 a -all</code>, and a DMARC record, <code>v=DMARC1; p=reject</code>, which has receivers refuse mail forged in the server's name - a false password-reset message among it; only the panel sends as this name, signed, so reject is safe. Server › Settings gives all three with the values to publish and whether they are in place, and its Re-check DNS checks them again once they are published; Server › Health shows them too. Without them notifications are still sent, and a receiver may file them as spam. Mail of your domains depends on none of them.</p></div>
         </div>
         <div class="box">
           <div class="sp-box-head"><span class="sp-no">05</span><h2>Account</h2></div>

docs/assets/panel-redesign/panel/src/settings.html

@@ -62,6 +62,18 @@
               <div class="field has-addons"><div class="control is-expanded"><input class="input" readonly value="v=spf1 a -all"></div><div class="control"><button type="button" class="button"><i class="ti ti-copy"></i>Copy</button></div></div></div>
             <p class="help">Notifications are sent without it, and a receiver may file them as spam.</p>
           </div>
+
+          <div class="sp-record">
+            <div class="sp-record-head"><h3>DMARC</h3><span class="tag is-warning is-light">missing</span><small>For the server's own name, not for your domains</small></div>
+            <div class="sp-row">
+              <div class="field"><label class="label">Host / name</label>
+                <div class="field has-addons"><div class="control is-expanded"><input class="input" readonly value="_dmarc.mail.example.org"></div><div class="control"><button type="button" class="button"><i class="ti ti-copy"></i>Copy</button></div></div></div>
+              <div class="field"><label class="label">Type</label><div class="control"><input class="input" readonly value="TXT"></div></div>
+            </div>
+            <div class="field"><label class="label">Value to publish</label>
+              <div class="field has-addons"><div class="control is-expanded"><input class="input" readonly value="v=DMARC1; p=reject"></div><div class="control"><button type="button" class="button"><i class="ti ti-copy"></i>Copy</button></div></div></div>
+            <p class="help">Without it a receiver does not refuse mail forged in the server's name - a false password-reset message included. Only the panel sends as this name, signed, so reject is safe.</p>
+          </div>
         </div>
 
         <div class="box" id="rate-limits">