Mini project on my own to discover Go.
- Email address syntax: https://en.wikipedia.org/wiki/Email_address#Local-part
- What is a DNS MX record ? https://www.cloudflare.com/learning/dns/dns-records/dns-mx-record/
- What is an SPF record ? https://support.dnsimple.com/articles/spf-record/
- What is a DMARC record ? https://dmarc.org/overview/
- Why are we checking those ? https://www.techtarget.com/searchsecurity/answer/Email-authentication-How-SPF-DKIM-and-DMARC-work-together