import { BoundaryConvertedData, BoundaryRawData, EmlContent, BuildOptions } from './interface';
/**
 * create a boundary
 */
export declare const createBoundary: () => string;
/**
 * Convert BoundaryRawData to BoundaryConvertedData
 * @param {BoundaryRawData} boundary
 * @returns {BoundaryConvertedData} Obj
 */
export declare const completeBoundary: (boundary: BoundaryRawData) => BoundaryConvertedData | null;
export declare const build: (data: EmlContent, options?: BuildOptions) => string;