From 56be7ae8c8661655a4f9bdcd869c16ba55f68d55 Mon Sep 17 00:00:00 2001 From: Dennis Baaten Date: Mon, 23 Sep 2019 19:09:48 +0200 Subject: [PATCH] Update DMARC-how-to.md --- DMARC-how-to.md | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) diff --git a/DMARC-how-to.md b/DMARC-how-to.md index afa6ece..cf0dbf1 100644 --- a/DMARC-how-to.md +++ b/DMARC-how-to.md @@ -23,10 +23,8 @@ DMARC addresses this problem and enables the owner of a domain to take explicit * When using office 365, the forwarding of calendar appointments from a DMARC projected domain fails. This is a known issue. Read more on the [Office 365 UserVoice forum](https://office365.uservoice.com/forums/264636-general/suggestions/34012756-forwarding-of-calendar-appointments-from-a-dmarc-p) and don't forget to submit your vote! * There is a workaround: Forward the appointment as an "iCalendar file" or as an attachment. -# Creating a DMARC record -The DMARC policy is published by means of a DNS TXT record. Before setting up a DMARC record, lets first take a look at all the configuration tags that can be configured within a DMARC record. - -## Overview of DMARC configuration tag +# Overview of DMARC configuration tags +The DMARC policy is published by means of a DNS TXT record. A DMARC record can contain several configuration tags. The table below will list all configuration tags and explain their purpose. | DMARC configuration tag | Required? | Value(s) | Explanation | | --- | --- | --- | --- | @@ -44,11 +42,6 @@ The DMARC policy is published by means of a DNS TXT record. Before setting up a Be aware that implementing a DMARC record without a rua configuration is possible, this is not advised because the DMARC XML files that are received by implementing a rua email address can help with implementing DKIM or SPF to meet the DMARC requirements. -## Setting up a DMARC record -Depending on your preferences and needs, you can determine the value of the configuration tags. The values below seem like a good starting point when setting up - - _dmarc IN TXT "v=DMARC1; p=quarantine; rua=mailto:dmarc@example.nl; ruf=mailto:dmarc@example.nl; fo=0; adkim=r; aspf=r; pct=100; rf=afrf; ri=86400; sp=quarantine" - # Implementing DMARC with OpenDMARC for Postfix with SpamAssassin **Specifics for this setup** * Linux Debian 9.8 (Stretch) @@ -64,6 +57,13 @@ Depending on your preferences and needs, you can determine the value of the conf ## Outbound e-mail traffic DMARC for outbound e-mail traffic can be accomplished by publishing a DMARC policy as a TXT record in a domain name's DNS zone. +### Setting up a DMARC record +Depending on your preferences and needs, you can determine the value of the configuration tags. The values below seem like a good starting point when setting up DMARC. + + _dmarc IN TXT "v=DMARC1; p=quarantine; rua=mailto:dmarc@example.nl; ruf=mailto:dmarc@example.nl; fo=0; adkim=r; aspf=r; pct=100; rf=afrf; ri=86400; sp=quarantine" + +Because this specific setup uses SpamAssassin for classifying e-mail to be SPAM or legitimate (HAM), the DMARC policy used is quarantine. This is done to prevent OpenDMARC from blocking the e-mail and, as a result, not enabling SpamAssassin to do its job. + ## Inbound e-mail traffic DMARC for inbound e-mail traffic can be accomplished by setting up OpenDMARC and integrate it with Postfix.