import type { Attachment } from "../providers/interface.js";
/** Gmail and most SMTP servers cap messages around 25 MB (pre base64). */
export declare const MAX_ATTACHMENT_BYTES: number;
/** Hard cap on total attachment payload per message. */
export declare const MAX_TOTAL_ATTACHMENT_BYTES: number;
export declare function guessMimeType(filename: string): string;
/**
 * Load an attachment from a local filesystem path for inclusion in an
 * outgoing email. Paths must point to an existing regular file; symlinks
 * are resolved before size checks; binary data is read into memory.
 *
 * The CRLF-free filename placed in the returned Attachment is derived from
 * basename(path) so the caller never controls header fields directly.
 */
export declare function loadAttachmentFromPath(path: string): Attachment;
/** Load an array of attachment paths, enforcing an overall size cap. */
export declare function loadAttachments(paths: string[] | undefined): Attachment[] | undefined;