diff --git a/src/relay.rs b/src/relay.rs
index 6d574cd..1ac90dc 100644
--- a/src/relay.rs
+++ b/src/relay.rs
@@ -89,29 +89,30 @@ struct Job {
     body: Arc<Vec<u8>>,
     key_id: String,
     private_key: Arc<PrivateKey>,
+    inbox_url: reqwest::Url,
 }
 
-fn spawn_worker(client: Arc<reqwest::Client>, inbox: String) -> Sender<Job> {
+fn spawn_worker(client: Arc<reqwest::Client>) -> Sender<Job> {
     let (tx, mut rx) = channel(1024);
 
     tokio::spawn(async move {
         let mut errors = 0u32;
         let mut last_request = None;
 
-        while let Some(Job { post_url, actor_id, key_id, private_key, body }) = rx.next().await {
+        while let Some(Job { post_url, actor_id, key_id, private_key, body, inbox_url }) = rx.next().await {
             if errors > 0 && last_request.map_or(false, |last_request|
                 Instant::now() - last_request < Duration::from_secs(10) * errors
             ) {
                 // there have been errors, skip for time proportional
                 // to the number of subsequent errors
-                tracing::trace!("skip {} from {} to {}", post_url, actor_id, inbox);
+                tracing::trace!("skip {} from {} to {}", post_url, actor_id, inbox_url);
                 continue;
             }
 
-            tracing::debug!("relay {} from {} to {}", post_url, actor_id, inbox);
+            tracing::debug!("relay {} from {} to {}", post_url, actor_id, inbox_url);
             last_request = Some(Instant::now());
             if let Err(e) = send::send_raw(
-                &client, &inbox,
+                &client, inbox_url.as_str(),
                 &key_id, &private_key, body
             ).await {
                 tracing::error!("relay::send {:?}", e);
@@ -179,25 +180,34 @@ pub fn spawn(
                     "object": &post.uri,
                     "id": *post_url,
                 });
+                let Ok(post_url_url) = reqwest::Url::parse(&post_url) else { continue; };
                 let body = Arc::new(
                     serde_json::to_vec(&body)
                         .unwrap()
                 );
                 for inbox in database.get_following_inboxes(&actor_id).await.unwrap() {
+                    let Ok(inbox_url) = reqwest::Url::parse(&inbox) else { continue; };
+
+                    // Avoid duplicate processing.
                     if seen_inboxes.contains(&inbox) {
                         continue;
                     }
-                    seen_inboxes.insert(inbox.clone());
+                    seen_inboxes.insert(inbox);
 
+
+                    // Lookup/create worker queue per inbox.
+                    let tx = workers.entry(inbox_url.host_str().unwrap_or("").to_string())
+                        .or_insert_with(|| spawn_worker(client.clone()));
+                    // Create queue item.
                     let job = Job {
                         post_url: post_url.clone(),
                         actor_id: actor_id.clone(),
                         body: body.clone(),
                         key_id: actor.key_id(),
                         private_key: private_key.clone(),
+                        inbox_url,
                     };
-                    let tx = workers.entry(inbox.clone())
-                        .or_insert_with(|| spawn_worker(client.clone(), inbox.clone()));
+                    // Enqueue job for worker.
                     let _ = tx.try_send(job);
                 }