/**
 * Email provider for MCP servers.
 *
 * Uses Gmail REST API with domain-wide delegation.
 * Edge-compatible (fetch + jose, no Node.js-only dependencies).
 *
 * Required env vars:
 *   GOOGLE_SERVICE_ACCOUNT_EMAIL  -  GCP service account email
 *   GOOGLE_PRIVATE_KEY            -  RSA private key (PKCS8 PEM)
 *   EMAIL_FROM                    -  sender address (e.g. noreply@revealui.com)
 *   EMAIL_REPLY_TO                -  default reply-to (e.g. support@revealui.com)
 */
export interface EmailPayload {
    from: string;
    to: string | string[];
    subject: string;
    html?: string;
    text?: string;
    reply_to?: string;
    tags?: Array<{
        name: string;
        value: string;
    }>;
}
export interface EmailResult {
    provider: 'gmail';
    id?: string;
    data?: unknown;
}
/**
 * Send a single email via Gmail REST API.
 */
export declare function sendEmail(payload: EmailPayload, overrides?: Record<string, string>): Promise<EmailResult>;
/**
 * Send a batch of emails via Gmail (sent individually  -  Gmail has no batch endpoint).
 */
export declare function sendEmailBatch(payloads: EmailPayload[], overrides?: Record<string, string>): Promise<EmailResult>;
//# sourceMappingURL=_email-provider.d.ts.map