Struct ConfigBuilder 

pub struct ConfigBuilder(/* private fields */);

Builder for Config.

Implementations

impl ConfigBuilder

pub fn strictness(self, s: Strictness) -> Self

Set RFC strictness level.

pub fn strip_subaddress(self) -> Self

Strip subaddress from canonical form.

pub fn preserve_subaddress(self) -> Self

Keep subaddress in canonical form (default).

pub fn subaddress_separator(self, sep: char) -> Self

Set the subaddress separator character (default: +).

pub fn dots_gmail_only(self) -> Self

Strip dots only for Gmail/Googlemail.

pub fn dots_always_strip(self) -> Self

Always strip dots from local part.

pub fn dots_preserve(self) -> Self

Preserve dots (default).

pub fn lowercase_all(self) -> Self

Lowercase both local part and domain.

pub fn lowercase_domain(self) -> Self

Lowercase domain only (default, RFC-correct).

pub fn preserve_case(self) -> Self

Preserve original case for local part (domain is always lowercased per RFC 5321).

pub fn domain_check_psl(self) -> Self

Validate domain against Public Suffix List (requires psl feature).

pub fn domain_check_tld(self) -> Self

Validate domain has a recognized TLD.

pub fn check_confusables(self) -> Self

Enable anti-homoglyph confusable detection.

pub fn allow_domain_literal(self) -> Self

Allow domain literals like [192.168.1.1].

pub fn allow_display_name(self) -> Self

Allow display names like "John Doe" <john@example.com>.

pub fn allow_single_label_domain(self) -> Self

Do not require a dot in the domain (allow single-label domains).

pub fn domain_check_syntax(self) -> Self

Syntax-only domain check (default). Resets from Psl/Tld back to syntax.

pub fn provider_aware(self) -> Self

Enable provider-aware normalization.

When enabled, an address whose domain matches a registered ProviderRule is normalized by that provider’s rule (dot stripping, case folding, subaddress separator) instead of the global policies. Addresses with no matching provider still use the global policies.

Provider lookups for is_freemail work regardless of this setting — it only gates normalization.

pub fn add_provider(self, rule: ProviderRule) -> Self

Register a custom ProviderRule, extending the built-in registry.

User rules take precedence over built-ins for the same domain, so this can also redefine a built-in provider. Affects is_freemail always, and normalization when provider_aware is set.

pub fn providers(self, registry: ProviderRegistry) -> Self

Replace the entire provider registry (e.g. start from ProviderRegistry::empty).

pub fn build(self) -> Config

Build the config.