DMARC Alignment: What is it and why is it important?

Quoted on this wiki

Every place a page here uses this source, in the order the words come in it.

1. Why does my email fail DMARC even though my SPF record says ‘pass’?This is a common situation. Third-party senders like Mailchimp or SendGrid often use their own domain as the Return-Path domain. This causes the unalignment of your ‘From-domain’. Contact your email provider to set up a custom Return-Path domain. “To align DKIM, add the TXT or CNAME records they provide to your DNS.” Does DMARC alignment affect my subdomains?Yes. By default, all subdomains inherit the parent domain’s policy. Use the ‘sp’ tag if you want to apply a different policy for subdomains. For example, the parent domain has p=reject, but you want to monitor without enforcement on your subdomains, add: ‘sp=none’ to the DMARC record of the parent domain.

   In Third-party sender authentication

2. Why does my email fail DMARC even though my SPF record says ‘pass’?This is a common situation. Third-party senders like Mailchimp or SendGrid often use their own domain as the Return-Path domain. This causes the unalignment of your ‘From-domain’. Contact your email provider to set up a custom Return-Path domain. “For SPF, add their ‘include’ to your SPF record and configure a custom Return-Path domain.” Does DMARC alignment affect my subdomains?Yes. By default, all subdomains inherit the parent domain’s policy. Use the ‘sp’ tag if you want to apply a different policy for subdomains. For example, the parent domain has p=reject, but you want to monitor without enforcement on your subdomains, add: ‘sp=none’ to the DMARC record of the parent domain.

   In Third-party sender authentication