/**
* Suppression store — persistent record of recipients who must not
* receive mail. Unifies bounces, complaints, and opt-outs across every
* driver we ship.
*
* @module
*/
import type { MaybePromise } from "../types.mjs";
export type SuppressionReason = "bounce" | "complaint" | "unsubscribed" | "manual" | "invalid" | string;
export interface SuppressionRecord {
	recipient: string;
	reason: SuppressionReason;
	source?: string;
	at: Date;
}
export interface SuppressionStore {
	has: (recipient: string) => MaybePromise<SuppressionRecord | null>;
	add: (recipient: string, reason: SuppressionReason, source?: string) => MaybePromise<void>;
	remove: (recipient: string) => MaybePromise<void>;
	list?: () => MaybePromise<ReadonlyArray<SuppressionRecord>>;
}
/** Options for `memorySuppressionStore`. */
export interface MemorySuppressionStoreOptions {
	/** Injectable clock for deterministic tests. */
	now?: () => number;
}
/** In-memory store. Recipients are normalized to lowercase. */
export declare function memorySuppressionStore(opts?: MemorySuppressionStoreOptions): SuppressionStore;
/** Minimal unstorage-like contract (decoupled so we don't bind the
*  dependency). Mirrors the shape already used by `src/queue`. */
interface UnstorageLike {
	getItem: (key: string) => MaybePromise<unknown>;
	setItem: (key: string, value: unknown) => MaybePromise<void>;
	removeItem: (key: string) => MaybePromise<void>;
	getKeys?: (base?: string) => MaybePromise<ReadonlyArray<string>>;
}
/** Persist suppressions to any `unstorage` driver (KV, Redis,
*  filesystem, …). Keys are prefixed with `suppression:`. */
export declare function unstorageSuppressionStore(storage: UnstorageLike): SuppressionStore;
export {};