type PostalMessageInput = {
    to: string[];
    subject: string;
    plainBody: string;
    htmlBody: string;
};
type PostalClient = {
    enabled: boolean;
    sendMessage: (input: PostalMessageInput) => Promise<void>;
};
type CreatePostalClientOptions = {
    baseUrl: string;
    apiKey: string;
    from: string;
    fetchImpl?: typeof fetch;
};
type CreatePostalClientFromEnvOptions = {
    baseUrlEnv?: string;
    apiKeyEnv?: string;
    fromEnv?: string;
    env?: Record<string, string | undefined>;
    fetchImpl?: typeof fetch;
};
declare function createPostalClient(options: CreatePostalClientOptions): PostalClient;
declare function createPostalClientFromEnv(options?: CreatePostalClientFromEnvOptions): PostalClient;

export { type CreatePostalClientOptions, type PostalClient, type PostalMessageInput, createPostalClient, createPostalClientFromEnv };