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pages:howtos:mailserver:dmarc [2023/10/22 13:12] mischerhpages:howtos:mailserver:dmarc [2023/10/22 14:22] (current) mischerh
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 {{tag>howto dmarc dkim spf mailserver email dig dns}} {{tag>howto dmarc dkim spf mailserver email dig dns}}
 ====== DMARC ====== ====== DMARC ======
 +  * https://support.google.com/a/answer/2466580
   * https://dmarc.org/2015/08/receiving-dmarc-reports-outside-your-domain/   * https://dmarc.org/2015/08/receiving-dmarc-reports-outside-your-domain/
 +  * https://powerdmarc.com/de/how-to-find-dkim-selector/
   * https://mxtoolbox.com/DMARCRecordGenerator.aspx?   * https://mxtoolbox.com/DMARCRecordGenerator.aspx?
 +  * https://easydmarc.com/tools/dkim-record-generator
 +  * https://www.agari.com/blog/dkim-setup
   * https://mxtoolbox.com/problem/dmarc/dmarc-external-validation?page=prob_dmarc   * https://mxtoolbox.com/problem/dmarc/dmarc-external-validation?page=prob_dmarc
   * https://dmarcadvisor.com/de/was-ist-external-destination-verification/   * https://dmarcadvisor.com/de/was-ist-external-destination-verification/
 +  * https://www.sidn.nl/en/news-and-blogs/hands-on-implementing-spf-dkim-and-dmarc-in-postfix <- THIS IS GOLD!
 +  * https://www.synology-forum.de/threads/strato-und-mail-server-einrichtung-dkim-spf-dmarc-workaround.92191/
 +  * https://powerdmarc.com/how-to-read-dmarc-reports/
 +  * https://www.mailercheck.com/articles/how-to-read-a-dmarc-report-and-actually-understand-it
 +
 +Open Source DMARC-Report Analyzers/Visualizer:
 +  * https://domainaware.github.io/parsedmarc/
  
 <sxh bash; gutter: false> <sxh bash; gutter: false>
 #MX #MX
 dig -t MX +noall +answer netzwerkforensik.com dig -t MX +noall +answer netzwerkforensik.com
 +dig +noall +answer netzwerkforensik.com
 +</sxh>
 +<code>
 +netzwerkforensik.com.   150     IN      MX      5 smtpin.rzone.de.
 +</code>
 +<code>
 +smtpin.rzone.de.        1800    IN      A       81.169.145.97
 +</code>
  
 +<sxh bash; gutter: false>
 # SPF # SPF
 dig -t txt +noall +answer _spf.strato.com dig -t txt +noall +answer _spf.strato.com
 dig -t txt +noall +answer netzwerkforensik.com dig -t txt +noall +answer netzwerkforensik.com
 +</sxh>
 +<code>
 +_spf.strato.com.        3600    IN      TXT     "v=spf1 ip4:81.169.146.128/25 ip4:85.215.255.0/24 ip6:2a01:238:20a:202::0/64 ip6:2a01:238:400::0/48 ip4:81.169.144.153 ip6:2a01:238:20a:202:50ff::153 -all"
 +</code>
 +<code>
 +netzwerkforensik.com.   150     IN      TXT     "v=spf1 include:_spf.strato.com mx -all"
 +</code>
  
 +<sxh bash; gutter: false>
 #DKIM Selector 1 #DKIM Selector 1
 dig -t txt +noall +answer strato-dkim-0002._domainkey.netzwerkforensik.com dig -t txt +noall +answer strato-dkim-0002._domainkey.netzwerkforensik.com
 +</sxh>
 +<code>
 +strato-dkim-0002._domainkey.netzwerkforensik.com. 150 IN TXT "v=DKIM1; k=rsa; p=MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAt3a1nbhQdD0MtbPT1r8DGZefoQlj3fSgtWdINsXsRl55OmOAf2QNR8B0SwC59dWqA+isuH/bQnU0f0OmO5A7p+cyfT9EekbWslP575NAnAYpsUJlBv/0O8qA6T/cLoDz6LsUYv000gFRqSSUe1BZnJ/sjg0f96UCkomT1aQRpSUSDwNYCqpQKQ/fWg9IS2fL+" "d2kR1rckqwoKdgbEtjr4i+ICn2SUodI1KkGusIivuBueMYfDh8RGYKvFv40UZlBSfuX71GkzEPvQPnQTfXLqM9F8q1kWq/mdWYy5R0KrWptAnuAmCZqujkgWmcqzLoTMln04oOxGFp/zkf8iA75lwIDAQAB"
 +</code>
  
 +<sxh bash; gutter: false>
 #DKIM Selector 2 #DKIM Selector 2
 dig -t txt +noall +answer strato-dkim-0003._domainkey.netzwerkforensik.com dig -t txt +noall +answer strato-dkim-0003._domainkey.netzwerkforensik.com
 +</sxh>
 +<code>
 +strato-dkim-0003._domainkey.netzwerkforensik.com. 150 IN TXT "v=DKIM1; k=ed25519; p=hB4fidO1tsRNeRkj6ySb9N2xwfNzERRFYLQhGQyQ9dE="
 +</code>
  
 +<sxh bash; gutter: false>
 #DMARC #DMARC
 dig -t txt +noall +answer _dmarc.netzwerkforensik.com dig -t txt +noall +answer _dmarc.netzwerkforensik.com
 dig -t txt +noall +answer netzwerkforensik.com._report._dmarc.wiretrip.de dig -t txt +noall +answer netzwerkforensik.com._report._dmarc.wiretrip.de
 </sxh> </sxh>
 +<code>
 +_dmarc.netzwerkforensik.com. 150 IN     TXT     "v=DMARC1; p=quarantine; rua=mailto:dmarc-report@wiretrip.de; ruf=mailto:postmaster@wiretrip.de; sp=reject; fo=0:1:d:s; pct=100; aspf=s"
 +</code>
 +<code>
 +netzwerkforensik.com._report._dmarc.wiretrip.de. 43200 IN TXT "v=DMARC1;"
 +</code>
 +
 +<sxh xml; highlight: []; title: dmarc report>
 +<?xml version="1.0" encoding="UTF-8" ?>
 +<feedback>
 +  <report_metadata>
 +    <org_name>google.com</org_name>
 +    <email>noreply-dmarc-support@google.com</email>
 +    <extra_contact_info>https://support.google.com/a/answer/2466580</extra_contact_info>
 +    <report_id>6934733341335759686</report_id>
 +    <date_range>
 +      <begin>1697673600</begin>
 +      <end>1697759999</end>
 +    </date_range>
 +  </report_metadata>
 +  <policy_published>
 +    <domain>netzwerkforensik.com</domain>
 +    <adkim>r</adkim>
 +    <aspf>s</aspf>
 +    <p>quarantine</p>
 +    <sp>reject</sp>
 +    <pct>100</pct>
 +    <np>reject</np>
 +  </policy_published>
 +  <record>
 +    <row>
 +      <source_ip>81.169.146.220</source_ip>
 +      <count>1</count>
 +      <policy_evaluated>
 +        <disposition>none</disposition>
 +        <dkim>pass</dkim>
 +        <spf>pass</spf>
 +      </policy_evaluated>
 +    </row>
 +    <identifiers>
 +      <header_from>netzwerkforensik.com</header_from>
 +    </identifiers>
 +    <auth_results>
 +      <dkim>
 +        <domain>netzwerkforensik.com</domain>
 +        <result>pass</result>
 +        <selector>strato-dkim-0002</selector>
 +      </dkim>
 +      <dkim>
 +        <domain>netzwerkforensik.com</domain>
 +        <result>fail</result>
 +        <selector></selector>
 +      </dkim>
 +      <spf>
 +        <domain>netzwerkforensik.com</domain>
 +        <result>pass</result>
 +      </spf>
 +    </auth_results>
 +  </record>
 +</feedback>
 +</sxh>
 +
 +Der Fail in Zeile 43 kommt vermutlich vom zweiten Selector 0003 weil das kein RSA sondern ED25519 Zertifikat ist und google das noch nicht unterstützt. Sollte aber neutral bewertet werden - also Selector 1: pass und Selector 2: neutral.
 +
 +===== Mail-tester-Ergebnis =====
 +  * https://www.mail-tester.com/test-trw64bcwh
  
 +{{:pages:howtos:mailserver:screenshot-2023-10-22-at-16-20-58-spam-test-result.png?direct&600|}}
 ---- ----
 ~~DISCUSSION~~ ~~DISCUSSION~~
  
pages/howtos/mailserver/dmarc.1697980363.txt.gz · Last modified: 2023/10/22 13:12 by mischerh