diff --git a/src/Protocol/ActivityPub/Transmitter.php b/src/Protocol/ActivityPub/Transmitter.php
index c1443bc331..ed1ac43c76 100644
--- a/src/Protocol/ActivityPub/Transmitter.php
+++ b/src/Protocol/ActivityPub/Transmitter.php
@@ -469,6 +469,21 @@ class Transmitter
 		return $permissions;
 	}
 
+	/**
+	 * Check if the given item id is from ActivityPub
+	 *
+	 * @param integer $item_id
+	 * @return boolean "true" if the post is from ActivityPub
+	 */
+	private static function isAPPost(int $item_id)
+	{
+		if (empty($item_id)) {
+			return false;
+		}
+
+		return Item::exists(['id' => $item_id, 'network' => Protocol::ACTIVITYPUB]);
+	}
+
 	/**
 	 * Creates an array of permissions from an item thread
 	 *
@@ -501,7 +516,7 @@ class Transmitter
 			$always_bcc = true;
 		}
 
-		if (self::isAnnounce($item) || DI::config()->get('debug', 'total_ap_delivery')) {
+		if (self::isAnnounce($item) || DI::config()->get('debug', 'total_ap_delivery') || self::isAPPost($last_id)) {
 			// Will be activated in a later step
 			$networks = Protocol::FEDERATED;
 		} else {
@@ -680,12 +695,13 @@ class Transmitter
 	 *
 	 * @param integer $uid      User ID
 	 * @param boolean $personal fetch personal inboxes
+	 * @param boolean $all_ap   Retrieve all AP enabled inboxes
 	 *
 	 * @return array of follower inboxes
 	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 * @throws \ImagickException
 	 */
-	public static function fetchTargetInboxesforUser($uid, $personal = false)
+	public static function fetchTargetInboxesforUser($uid, $personal = false, bool $all_ap = false)
 	{
 		$inboxes = [];
 
@@ -698,7 +714,7 @@ class Transmitter
 			}
 		}
 
-		if (DI::config()->get('debug', 'total_ap_delivery')) {
+		if (DI::config()->get('debug', 'total_ap_delivery') || $all_ap) {
 			// Will be activated in a later step
 			$networks = Protocol::FEDERATED;
 		} else {
@@ -793,7 +809,7 @@ class Transmitter
 				}
 
 				if ($item_profile && ($receiver == $item_profile['followers']) && ($uid == $profile_uid)) {
-					$inboxes = array_merge($inboxes, self::fetchTargetInboxesforUser($uid, $personal));
+					$inboxes = array_merge($inboxes, self::fetchTargetInboxesforUser($uid, $personal, self::isAPPost($last_id)));
 				} else {
 					if (Contact::isLocal($receiver)) {
 						continue;
@@ -1033,33 +1049,31 @@ class Transmitter
 			return false;
 		}
 
-		if (empty($type)) {
-			$condition = ['item-uri' => $item['uri'], 'protocol' => Conversation::PARCEL_ACTIVITYPUB];
-			$conversation = DBA::selectFirst('conversation', ['source'], $condition);
-			if (DBA::isResult($conversation)) {
-				$data = json_decode($conversation['source'], true);
-				if (!empty($data['type'])) {
-					if (in_array($data['type'], ['Create', 'Update'])) {
-						if ($object_mode) {
-							unset($data['@context']);
-							unset($data['signature']);
-						}
-						Logger::info('Return stored conversation', ['item' => $item_id]);
-						return $data;
-					} elseif (in_array('as:' . $data['type'], Receiver::CONTENT_TYPES)) {
-						if (!empty($data['@context'])) {
-							$context = $data['@context'];
-							unset($data['@context']);
-						}
-						unset($data['actor']);
-						$object = $data;
+		$condition = ['item-uri' => $item['uri'], 'protocol' => Conversation::PARCEL_ACTIVITYPUB];
+		$conversation = DBA::selectFirst('conversation', ['source'], $condition);
+		if (!$item['origin'] && DBA::isResult($conversation)) {
+			$data = json_decode($conversation['source'], true);
+			if (!empty($data['type'])) {
+				if (in_array($data['type'], ['Create', 'Update'])) {
+					if ($object_mode) {
+						unset($data['@context']);
+						unset($data['signature']);
 					}
+					Logger::info('Return stored conversation', ['item' => $item_id]);
+					return $data;
+				} elseif (in_array('as:' . $data['type'], Receiver::CONTENT_TYPES)) {
+					if (!empty($data['@context'])) {
+						$context = $data['@context'];
+						unset($data['@context']);
+					}
+					unset($data['actor']);
+					$object = $data;
 				}
 			}
-
-			$type = self::getTypeOfItem($item);
 		}
 
+		$type = self::getTypeOfItem($item);
+
 		if (!$object_mode) {
 			$data = ['@context' => $context ?? ActivityPub::CONTEXT];
 
diff --git a/src/Protocol/Diaspora.php b/src/Protocol/Diaspora.php
index 7ab41eb52b..54a8d1c1ba 100644
--- a/src/Protocol/Diaspora.php
+++ b/src/Protocol/Diaspora.php
@@ -3031,7 +3031,18 @@ class Diaspora
 			$owner['uprvkey'] = $owner['prvkey'];
 		}
 
-		$envelope = self::buildMessage($msg, $owner, $contact, $owner['uprvkey'], $contact['pubkey'], $public_batch);
+		// When sending content to Friendica contacts using the Diaspora protocol
+		// we have to fetch the public key from the fcontact.
+		// This is due to the fact that legacy DFRN had unique keys for every contact.
+		$pubkey = $contact['pubkey'];
+		if (!empty($contact['addr'])) {
+			$fcontact = FContact::getByURL($contact['addr']);
+			if (!empty($fcontact)) {
+				$pubkey = $fcontact['pubkey'];
+			}
+		}
+
+		$envelope = self::buildMessage($msg, $owner, $contact, $owner['uprvkey'], $pubkey, $public_batch);
 
 		$return_code = self::transmit($owner, $contact, $envelope, $public_batch, $guid);
 
diff --git a/src/Worker/Delivery.php b/src/Worker/Delivery.php
index 8a84f34a2f..1d1e8702b2 100644
--- a/src/Worker/Delivery.php
+++ b/src/Worker/Delivery.php
@@ -141,13 +141,7 @@ class Delivery
 				}
 			}
 
-			// When commenting too fast after delivery, a post wasn't recognized as top level post.
-			// The count then showed more than one entry. The additional check should help.
-			// The check for the "count" should be superfluous, but I'm not totally sure by now, so we keep it.
-			if ((($parent['id'] == $target_id) || (count($items) == 1)) && ($parent['uri'] === $parent['parent-uri'])) {
-				Logger::log('Top level post');
-				$top_level = true;
-			}
+			$top_level = $target_item['gravity'] == GRAVITY_PARENT;
 
 			// This is IMPORTANT!!!!
 
@@ -211,7 +205,8 @@ class Delivery
 		// Transmit via Diaspora if the thread had started as Diaspora post.
 		// Also transmit via Diaspora if this is a direct answer to a Diaspora comment.
 		// This is done since the uri wouldn't match (Diaspora doesn't transmit it)
-		if (!empty($parent) && !empty($thr_parent) && in_array(Protocol::DIASPORA, [$parent['network'], $thr_parent['network']])) {
+		// Also transmit relayed posts from Diaspora contacts via Diaspora.
+		if (!empty($parent) && !empty($thr_parent) && in_array(Protocol::DIASPORA, [$parent['network'], $thr_parent['network'], $target_item['network']])) {
 			$contact['network'] = Protocol::DIASPORA;
 		}
 
diff --git a/src/Worker/Notifier.php b/src/Worker/Notifier.php
index 7359ad1d47..3be00359e5 100644
--- a/src/Worker/Notifier.php
+++ b/src/Worker/Notifier.php
@@ -133,10 +133,7 @@ class Notifier
 				}
 			}
 
-			if ((count($items) == 1) && ($items[0]['id'] === $target_item['id']) && ($items[0]['uri'] === $items[0]['parent-uri'])) {
-				Logger::info('Top level post', ['target' => $target_id]);
-				$top_level = true;
-			}
+			$top_level = $target_item['gravity'] == GRAVITY_PARENT;
 		}
 
 		$owner = User::getOwnerDataById($uid);
@@ -774,11 +771,16 @@ class Notifier
 			return 0;
 		}
 
-		// Also don't deliver  when the direct thread parent was delivered via Diaspora
+		// Also don't deliver when the direct thread parent was delivered via Diaspora
 		if ($thr_parent['network'] == Protocol::DIASPORA) {
 			return 0;
 		}
 
+		// Posts from Diaspora contacts are transmitted via Diaspora
+		if ($target_item['network'] == Protocol::DIASPORA) {
+			return 0;
+		}
+
 		$inboxes = [];
 		$relay_inboxes = [];