import type { AuthMethod } from "./auth.mjs";
/** Knobs mirror what's user-visible on `SmtpDriverOptions`. Kept narrow so
*  this module is easy to unit-test. */
export interface ConnectionOptions {
	host: string;
	port: number;
	secure: boolean;
	requireTLS?: boolean;
	user?: string;
	password?: string;
	authMethod?: AuthMethod | "AUTO";
	getAccessToken?: () => Promise<string>;
	rejectUnauthorized?: boolean;
	tls?: import("node:tls").ConnectionOptions;
	localName: string;
	connectionTimeoutMs: number;
	commandTimeoutMs: number;
}
export interface Capabilities {
	authMethods: Set<AuthMethod>;
	starttls: boolean;
	size: number;
	smtputf8: boolean;
}
/** A live SMTP connection. `sendMessage` handles MAIL FROM → RCPT TO →
*  DATA; callers can reuse the same instance for multiple messages via
*  `reset()` (issues `RSET`). */
export interface SmtpConnection {
	id: number;
	capabilities: Capabilities;
	sendMessage: (envelope: {
		from: string;
		rcpt: string[];
	}, body: string) => Promise<void>;
	reset: () => Promise<void>;
	quit: () => Promise<void>;
	destroy: () => void;
	isOpen: () => boolean;
}
/** Establish an SMTP connection: TCP connect → optional implicit TLS →
*  EHLO → optional STARTTLS → re-EHLO → AUTH. Returns when ready to send. */
export declare function createConnection(opts: ConnectionOptions): Promise<SmtpConnection>;