import * as yup from 'yup';
/** The email format both email schemas check. Presence — empty, `null`, `undefined` — is decided by the schema the caller picks. */
export declare const isValidEmail: (value: string) => boolean;
export declare const emailValidationSchema: () => yup.StringSchema<string, yup.AnyObject, undefined, "">;
export declare const nullableEmailValidationSchema: () => yup.StringSchema<string | null | undefined, yup.AnyObject, undefined, "">;