import type { StringSchemaOptions } from "./StringSchema.js";
import { StringSchema } from "./StringSchema.js";
/**
 * Define a valid email address.
 *
 * - Falsy values are converted to `""` empty string.
 * - Total length must be 254 characters or fewer (in SMTP email is encoded with `<` and `>` to make 256 characters).
 * - No minimum length is enforced because the email's format is enforced instead.
 * - RFC specifies username _should_ be case insensitive to avoid confusion.
 *     - We lowercase the entire address as a simple way to enforce this.
 *     - This is technically incorrect but practically better, and avoids case insensitive lookups in databases etc.
 * - Username portion must be 64 characters or fewer from the range `[a-z0-9.!#$%&’*+/=?^_`{|}~-]`
 *     - We subset this to `[a-z0-9._+-]` with no special characters at start/end (and we lowercase automatically).
 *     - If someone uses e.g. `*` asterisk at all or '-' at the start then it's most likely to be a mistake.
 * - Server portion must be a valid domain
 *     - Limited to `[a-z0-9]` with mid-word hyphens only.
 *     - Up to 10 segments of up to 63 characters each, separated by `.`
 *     - TLD is a segment of 2-63 characters, possibly in `xn--` international format.
 */
export declare class EmailSchema extends StringSchema {
    constructor({ one, title, ...options }: Omit<StringSchemaOptions, "type" | "min" | "max" | "match" | "rows">);
    sanitize(str: string): string;
}
/** Valid email, e.g. `test@test.com` */
export declare const EMAIL: EmailSchema;
/** Valid optional email, e.g. `test@test.com`, or `null` */
export declare const NULLABLE_EMAIL: import("./NullableSchema.js").NullableSchema<string>;