What are the DMARC tags I can use?
A DMARC record is made up of different tags which we'll go over below.
Required tags:
| v | Refers to the DMARC version (DMARC1;) | 
| p | Allows you to define the domain policy (none, quarantine, or reject | 
Optional tags:
| pct | The percentage of emails messages subject to filtering. When might I want to use this? | 
| rua | Reporting addresses for aggregate reports. This is where you tell receivers which address those reports should be sent to | 
| ruf | Allows you to specify the reporting addresses for forensic/failure reports. What are forensic reports? | 
| fo | Allows you to specify the type of failure reports you receive. 
 
       If you'd like to receive multiple types of failure reports, you can separate each type with a colon:  v=DMARC1; p=reject; rua=mailto:123@report.com; ruf=mailto:123@report.com; fo=0:1:d:s; | 
| aspf | Allows you to specify the alignment mode for SPF. Relaxed (r) or Strict (s) | 
| adkim | Allows you to specify the alignment mode for DKIM. Relaxed (r) or Strict (s). | 
| rf | Forensic report format. The default and currently only supported format is "afrf". | 
| ri | Reporting interval in seconds for aggregate reports. Aggregrate DMARC reports are sent daily by default. | 
| sp | Allows you to specify the DMARC policy for all subdomains. v=DMARC1; p=reject; rua=mailto:123@report.com; ruf=mailto:123@report.com; sp=none; | 
