import { type MIMEBuildResult } from "../core/mime.js";
import type { SMTPResponse } from "../core/smtp.js";
import { encodeLine } from "../core/smtp.js";
import type { MailOptions, SendResult, SMTPConfig, SocketAdapter, Transport, VerifyResult } from "../core/types.js";
/**
 * SMTP transport orchestrating adapter, MIME builder, and protocol logic.
 */
export declare class SMTPTransport implements Transport {
    readonly provider = "smtp";
    /** Resolved SMTP configuration with defaults applied. */
    private readonly config;
    /** Active socket adapter for the current session, if any. */
    private adapter;
    /** Creates an SMTP transport with the given configuration. */
    constructor(config: SMTPConfig);
    /** Sends an email via SMTP using the configured adapter. */
    send(options: MailOptions): Promise<SendResult>;
    /** Verifies SMTP connectivity and authentication without sending mail. */
    verify(): Promise<VerifyResult>;
    /** Closes the underlying socket adapter if connected. */
    close(): Promise<void>;
    /** Returns the configured socket adapter or throws if none is set. */
    private getAdapter;
}
/** Resolved SMTP transport configuration with defaults applied. */
export interface ResolvedSMTPConfig {
    /** SMTP server hostname. */
    host: string;
    /** SMTP port with secure/default applied. */
    port: number;
    /** Whether implicit TLS is used. */
    secure: boolean;
    /** Resolved authentication credentials, if any. */
    auth?: SMTPConfig["auth"];
    /** Whether AUTH requires an encrypted connection. */
    requireTLS?: boolean;
    /** TLS options for STARTTLS and direct TLS. */
    tls?: SMTPConfig["tls"];
    /** DKIM signing configuration. */
    dkim?: SMTPConfig["dkim"];
    /** Socket connect timeout in milliseconds. */
    connectionTimeout?: number;
    /** Timeout waiting for the SMTP greeting in milliseconds. */
    greetingTimeout?: number;
    /** Idle socket timeout in milliseconds. */
    socketTimeout?: number;
    /** Direct-to-MX delivery mode. */
    direct?: boolean;
    /** Runtime socket adapter. */
    adapter?: SocketAdapter;
}
/** Apply defaults to SMTP configuration. */
export declare function resolveSMTPConfig(config: SMTPConfig): ResolvedSMTPConfig;
/**
 * Connect greeting, EHLO, optional STARTTLS, and AUTH on an open adapter.
 */
export declare function openSMTPSession(adapter: SocketAdapter, config: ResolvedSMTPConfig): Promise<void>;
/**
 * MAIL FROM, RCPT TO, and DATA for a built MIME message on an authenticated session.
 */
export declare function deliverSMTPMessage(adapter: SocketAdapter, mime: MIMEBuildResult): Promise<SendResult>;
/**
 * QUIT and close an SMTP session adapter.
 */
export declare function closeSMTPSession(adapter: SocketAdapter): Promise<void>;
/** Reads and parses a complete SMTP response from the adapter. */
declare function readSMTPResponse(adapter: SocketAdapter): Promise<SMTPResponse>;
export { SMTPError } from "../core/smtp.js";
/** @internal Test helper for raw line writes. */
export { encodeLine, readSMTPResponse };