If you can see the Hutao above, your color space is P3.
Branded Mail gives business owners the ability to add a brand logo and name to their business emails, so that they can make emails stand out in Mail app.
You can add Branded Mail in three ways
Apple checks DNS records for DMARC (Domain-based Message Authentication, Reporting and Conformance), a TXT record in the domain's DNS record, to help prevent email spoofing and protect company's brand.
The following DMARC settings are required on your mail server's DNS record to use Branded Mail
An example DNS can be the following:
Type: TXT
Name: _dmarc
Content: "v=DMARC1; p=reject; pct=100;"