diff --git a/src/activitypub/inbox.js b/src/activitypub/inbox.js
index 19686a8bf8..80412aca8b 100644
--- a/src/activitypub/inbox.js
+++ b/src/activitypub/inbox.js
@@ -412,3 +412,14 @@ inbox.flag = async (req) => {
 		}
 	}));
 };
+
+inbox.reject = async (req) => {
+	const { actor, object } = req.body;
+	const { type, id } = object;
+	const { hostname } = new URL(actor);
+	const queueId = `${type}:${id}:${hostname}`;
+
+	// stop retrying rejected requests
+	clearTimeout(activitypub.retryQueue.get(queueId));
+	activitypub.retryQueue.delete(queueId);
+};
diff --git a/src/activitypub/index.js b/src/activitypub/index.js
index 357de15f9f..89d1fa0523 100644
--- a/src/activitypub/index.js
+++ b/src/activitypub/index.js
@@ -10,6 +10,7 @@ const meta = require('../meta');
 const user = require('../user');
 const utils = require('../utils');
 const ttl = require('../cache/ttl');
+const lru = require('../cache/lru');
 
 const requestCache = ttl({ ttl: 1000 * 60 * 5 }); // 5 minutes
 const ActivityPub = module.exports;
@@ -252,6 +253,40 @@ ActivityPub.get = async (type, id, uri) => {
 	}
 };
 
+ActivityPub.retryQueue = lru({ name: 'activitypub-retry-queue', max: 4000, ttl: 1000 * 60 * 60 * 24 * 60 });
+
+async function sendMessage(uri, id, type, payload, attempts = 1) {
+	const keyData = await ActivityPub.getPrivateKey(type, id);
+	const headers = await ActivityPub.sign(keyData, uri, payload);
+	winston.verbose(`[activitypub/send] ${uri}`);
+	try {
+		const { response, body } = await request.post(uri, {
+			headers: {
+				...headers,
+				'content-type': 'application/ld+json; profile="https://www.w3.org/ns/activitystreams"',
+			},
+			body: payload,
+		});
+
+		if (String(response.statusCode).startsWith('2')) {
+			winston.verbose(`[activitypub/send] Successfully sent ${payload.type} to ${uri}`);
+		} else {
+			throw new Error(String(body));
+		}
+	} catch (e) {
+		winston.warn(`[activitypub/send] Could not send ${payload.type} to ${uri}; error: ${e.message}`);
+		// add to retry queue
+		if (attempts < 12) { // stop attempting after ~2 months
+			const timeout = (4 ** attempts) * 1000; // exponential backoff
+			const queueId = `${payload.type}:${payload.id}:${new URL(uri).hostname}`;
+			const timeoutId = setTimeout(() => sendMessage(uri, id, type, payload, attempts + 1), timeout);
+			ActivityPub.retryQueue.set(queueId, timeoutId);
+
+			winston.verbose(`[activitypub/send] Added ${payload.type} to ${uri} to retry queue for ${timeout}ms`);
+		}
+	}
+}
+
 ActivityPub.send = async (type, id, targets, payload) => {
 	if (!Array.isArray(targets)) {
 		targets = [targets];
@@ -267,26 +302,5 @@ ActivityPub.send = async (type, id, targets, payload) => {
 		...payload,
 	};
 
-	await Promise.all(inboxes.map(async (uri) => {
-		const keyData = await ActivityPub.getPrivateKey(type, id);
-		const headers = await ActivityPub.sign(keyData, uri, payload);
-		winston.verbose(`[activitypub/send] ${uri}`);
-		try {
-			const { response, body } = await request.post(uri, {
-				headers: {
-					...headers,
-					'content-type': 'application/ld+json; profile="https://www.w3.org/ns/activitystreams"',
-				},
-				body: payload,
-			});
-
-			if (String(response.statusCode).startsWith('2')) {
-				winston.verbose(`[activitypub/send] Successfully sent ${payload.type} to ${uri}`);
-			} else {
-				winston.warn(`[activitypub/send] Could not send ${payload.type} to ${uri}; error: ${String(body)}`);
-			}
-		} catch (e) {
-			winston.warn(`[activitypub/send] Could not send ${payload.type} to ${uri}; error: ${e.message}`);
-		}
-	}));
+	await Promise.all(inboxes.map(async uri => sendMessage(uri, id, type, payload)));
 };