Crate structured_email_address 

structured-email-address

RFC 5321/5322/6531 conformant email address parser, validator, and normalizer.

Unlike existing Rust crates that stop at RFC validation, this crate provides:

• Subaddress extraction: user+tag@domain → separate user, tag, domain
• Provider-aware normalization: Gmail dot-stripping, configurable case folding
• PSL domain validation: verify domain against the Public Suffix List
• Anti-homoglyph protection: detect Cyrillic/Latin lookalikes via Unicode skeleton
• Configurable strictness: Strict (5321), Standard (5322), Lax (obs-* allowed)
• Zero-copy parsing: internal spans into the input string

Quick Start

use structured_email_address::{EmailAddress, Config};

// Simple: parse with defaults
let email: EmailAddress = "user+tag@example.com".parse().unwrap();
assert_eq!(email.local_part(), "user+tag");
assert_eq!(email.tag(), Some("tag"));
assert_eq!(email.domain(), "example.com");

// Configured: Gmail normalization pipeline
let config = Config::builder()
    .strip_subaddress()
    .dots_gmail_only()
    .lowercase_all()
    .build();

let email = EmailAddress::parse_with("A.L.I.C.E+promo@Gmail.COM", &config).unwrap();
assert_eq!(email.canonical(), "alice@gmail.com");
assert_eq!(email.tag(), Some("promo"));

Structs

Config

Configuration for email address parsing and normalization.

ConfigBuilder

Builder for Config.

EmailAddress

A parsed, validated, and normalized email address.

Error

Error returned when parsing or validating an email address fails.

Enums

CasePolicy

How to handle letter case.

DomainCheck

How to validate the domain.

DotPolicy

How to handle dots in the local part.

ErrorKind

The specific kind of error that occurred.

Strictness

How strictly to validate RFC grammar.

SubaddressPolicy

Whether to strip +subaddress tags.

Functions

confusable_skeleton

Compute confusable skeleton for anti-homoglyph protection.