diff --git a/src/receive_imf.rs b/src/receive_imf.rs
index 726edfc5f..557c5d8ae 100644
--- a/src/receive_imf.rs
+++ b/src/receive_imf.rs
@@ -1442,33 +1442,59 @@ async fn add_parts(
     }
 
     if let Some(node_addr) = mime_parser.get_header(HeaderDef::IrohNodeAddr) {
+        chat_id = DC_CHAT_ID_TRASH;
         match serde_json::from_str::<NodeAddr>(node_addr).context("Failed to parse node address") {
             Ok(node_addr) => {
                 info!(context, "Adding iroh peer with address {node_addr:?}.");
-                let instance_id = parent.context("Failed to get parent message")?.id;
-                context.emit_event(EventType::WebxdcRealtimeAdvertisementReceived {
-                    msg_id: instance_id,
-                });
-                if let Some(topic) = get_iroh_topic_for_msg(context, instance_id).await? {
-                    let node_id = node_addr.node_id;
-                    let relay_server = node_addr.relay_url().map(|relay| relay.as_str());
-                    iroh_add_peer_for_topic(context, instance_id, topic, node_id, relay_server)
-                        .await?;
-                    if context
-                        .get_config_bool(Config::WebxdcRealtimeEnabled)
-                        .await?
-                    {
-                        let iroh = context.get_or_try_init_peer_channel().await?;
-                        iroh.maybe_add_gossip_peers(topic, vec![node_addr]).await?;
+                match mime_parser.get_header(HeaderDef::InReplyTo) {
+                    Some(in_reply_to) => match rfc724_mid_exists(context, in_reply_to).await? {
+                        Some((instance_id, _ts_sent)) => {
+                            context.emit_event(EventType::WebxdcRealtimeAdvertisementReceived {
+                                msg_id: instance_id,
+                            });
+                            if let Some(topic) =
+                                get_iroh_topic_for_msg(context, instance_id).await?
+                            {
+                                let node_id = node_addr.node_id;
+                                let relay_server =
+                                    node_addr.relay_url().map(|relay| relay.as_str());
+                                iroh_add_peer_for_topic(
+                                    context,
+                                    instance_id,
+                                    topic,
+                                    node_id,
+                                    relay_server,
+                                )
+                                .await?;
+                                if context
+                                    .get_config_bool(Config::WebxdcRealtimeEnabled)
+                                    .await?
+                                {
+                                    let iroh = context.get_or_try_init_peer_channel().await?;
+                                    iroh.maybe_add_gossip_peers(topic, vec![node_addr]).await?;
+                                }
+                                info!(context, "Added iroh peer to the topic of {instance_id}.");
+                            } else {
+                                warn!(
+                                    context,
+                                    "Could not add iroh peer because {instance_id} has no topic."
+                                );
+                            }
+                        }
+                        None => {
+                            warn!(
+                                context,
+                                "Cannot add iroh peer because WebXDC instance does not exist."
+                            );
+                        }
+                    },
+                    None => {
+                        warn!(
+                            context,
+                            "Cannot add iroh peer because the message has no In-Reply-To."
+                        );
                     }
-                    info!(context, "Added iroh peer to the topic of {instance_id}.");
-                } else {
-                    warn!(
-                        context,
-                        "Could not add iroh peer because {instance_id} has no topic."
-                    );
                 }
-                chat_id = DC_CHAT_ID_TRASH;
             }
             Err(err) => {
                 warn!(context, "Couldn't parse NodeAddr: {err:#}.");