Regression in SPF_BUILDER using +mx #4042
Description
Is it expected for validation to fail in SPF_BUILDER .js when using +mx and overflow?
var REG_NONE = NewRegistrar("none");
var DNS_BIND = NewDnsProvider("bind");
D("example.com",
REG_NONE,
DnsProvider(DNS_BIND),
SPF_BUILDER({
overflow: "_spf%d", // REMOVE TO FIX
parts: [
"v=spf1",
"+mx", // accept from this domain's mx records
"-all", // reject all other mail servers
],
}),
)dnscontrol v4.32.0 returns the error:
2026/02/02 11:22:09 1 Validation errors:
2026/02/02 11:22:09 ERROR: unsupported SPF part mx
If the overflow field is removed, the validation passes without error.
This configuration worked previously.