stackexchange-dnscontrol/documentation/functions/domain/SOA.md

name	parameters	parameter_types
SOA	name ns mbox refresh retry expire minttl modifiers...	name ns mbox refresh retry expire minttl modifiers... string string string number number number number RecordModifier[]

SOA adds an SOA record to a domain. The name should be @. ns and mbox are strings. The other fields are unsigned 32-bit ints.

D("example.com", REG_THIRDPARTY, DnsProvider("DNS_BIND"),
  SOA("@", "ns3.example.org.", "hostmaster@example.org", 3600, 600, 604800, 1440),
);

The email address should be specified like a normal RFC822/RFC5322 address (user@hostname.com). It will be converted into the required format (e.g. BIND format: user.hostname.com) by the provider as required. This has the benefit of being more human-readable plus DNSControl can properly handle escaping and other issues.

Notes

• Previously, the accepted format for the SOA mailbox field was hostmaster.example.org. This has been changed to hostmaster@example.org
• The serial number is managed automatically. It isn't even a field in SOA().
• Most providers automatically generate SOA records. They will ignore any SOA() statements.

There is more info about SOA in the documentation for the BIND provider.