diff --git a/src/Model/Item.php b/src/Model/Item.php
index 1fc4be2f55..a19357635b 100644
--- a/src/Model/Item.php
+++ b/src/Model/Item.php
@@ -1355,7 +1355,7 @@ class Item
 	 * @param array $item
 	 * @return boolean item is valid
 	 */
-	private static function isValid(array $item)
+	public static function isValid(array $item)
 	{
 		// When there is no content then we don't post it
 		if ($item['body'].$item['title'] == '') {
@@ -1384,7 +1384,7 @@ class Item
 			}
 		}
 
-		if (Contact::isBlocked($item['author-id'])) {
+		if (!empty($item['author-id']) && Contact::isBlocked($item['author-id'])) {
 			Logger::notice('Author is blocked node-wide', ['author-link' => $item['author-link'], 'item-uri' => $item['uri']]);
 			return false;
 		}
@@ -1394,12 +1394,12 @@ class Item
 			return false;
 		}
 
-		if (!empty($item['uid']) && Contact\User::isBlocked($item['author-id'], $item['uid'])) {
+		if (!empty($item['uid']) && !empty($item['author-id']) && Contact\User::isBlocked($item['author-id'], $item['uid'])) {
 			Logger::notice('Author is blocked by user', ['author-link' => $item['author-link'], 'uid' => $item['uid'], 'item-uri' => $item['uri']]);
 			return false;
 		}
 
-		if (Contact::isBlocked($item['owner-id'])) {
+		if (!empty($item['owner-id']) && Contact::isBlocked($item['owner-id'])) {
 			Logger::notice('Owner is blocked node-wide', ['owner-link' => $item['owner-link'], 'item-uri' => $item['uri']]);
 			return false;
 		}
@@ -1409,7 +1409,7 @@ class Item
 			return false;
 		}
 
-		if (!empty($item['uid']) && Contact\User::isBlocked($item['owner-id'], $item['uid'])) {
+		if (!empty($item['uid']) && !empty($item['owner-id']) && Contact\User::isBlocked($item['owner-id'], $item['uid'])) {
 			Logger::notice('Owner is blocked by user', ['owner-link' => $item['owner-link'], 'uid' => $item['uid'], 'item-uri' => $item['uri']]);
 			return false;
 		}
diff --git a/src/Protocol/ActivityPub/Transmitter.php b/src/Protocol/ActivityPub/Transmitter.php
index 1ffe034d16..f1b2d3acc7 100644
--- a/src/Protocol/ActivityPub/Transmitter.php
+++ b/src/Protocol/ActivityPub/Transmitter.php
@@ -1547,7 +1547,7 @@ class Transmitter
 	 */
 	public static function isAnnounce($item)
 	{
-		if ($item['verb'] == Activity::ANNOUNCE) {
+		if (!empty($item['verb']) && ($item['verb'] == Activity::ANNOUNCE)) {
 			return true;
 		}
 
diff --git a/src/Protocol/Feed.php b/src/Protocol/Feed.php
index 1d68ff0e2a..ba0adb8347 100644
--- a/src/Protocol/Feed.php
+++ b/src/Protocol/Feed.php
@@ -35,7 +35,6 @@ use Friendica\Model\Contact;
 use Friendica\Model\Item;
 use Friendica\Model\Tag;
 use Friendica\Model\User;
-use Friendica\Network\HTTPRequest;
 use Friendica\Util\DateTimeFormat;
 use Friendica\Util\Network;
 use Friendica\Util\ParseUrl;
@@ -496,6 +495,14 @@ class Feed
 				$item["title"] = '';
 			}
 
+			if ($dryRun) {
+				$items[] = $item;
+				break;
+			} elseif (!Item::isValid($item)) {
+				Logger::info('Feed is invalid', ['created' => $item['created'], 'uid' => $item['uid'], 'uri' => $item['uri']]);
+				continue;
+			}
+
 			$preview = '';
 			if (!empty($contact["fetch_further_information"]) && ($contact["fetch_further_information"] < 3)) {
 				// Handle enclosures and treat them as preview picture
@@ -564,34 +571,29 @@ class Feed
 				}
 			}
 
-			if ($dryRun) {
-				$items[] = $item;
-				break;
-			} else {
-				Logger::info('Stored feed', ['item' => $item]);
+			Logger::info('Stored feed', ['item' => $item]);
 
-				$notify = Item::isRemoteSelf($contact, $item);
+			$notify = Item::isRemoteSelf($contact, $item);
 
-				// Distributed items should have a well formatted URI.
-				// Additionally we have to avoid conflicts with identical URI between imported feeds and these items.
-				if ($notify) {
-					$item['guid'] = Item::guidFromUri($orig_plink, DI::baseUrl()->getHostname());
-					unset($item['uri']);
-					unset($item['parent-uri']);
+			// Distributed items should have a well formatted URI.
+			// Additionally we have to avoid conflicts with identical URI between imported feeds and these items.
+			if ($notify) {
+				$item['guid'] = Item::guidFromUri($orig_plink, DI::baseUrl()->getHostname());
+				unset($item['uri']);
+				unset($item['parent-uri']);
 
-					// Set the delivery priority for "remote self" to "medium"
-					$notify = PRIORITY_MEDIUM;
-				}
+				// Set the delivery priority for "remote self" to "medium"
+				$notify = PRIORITY_MEDIUM;
+			}
 
-				$id = Item::insert($item, $notify);
+			$id = Item::insert($item, $notify);
 
-				Logger::info("Feed for contact " . $contact["url"] . " stored under id " . $id);
+			Logger::info("Feed for contact " . $contact["url"] . " stored under id " . $id);
 
-				if (!empty($id) && !empty($taglist)) {
-					$feeditem = Item::selectFirst(['uri-id'], ['id' => $id]);
-					foreach ($taglist as $tag) {
-						Tag::store($feeditem['uri-id'], Tag::HASHTAG, $tag);
-					}					
+			if (!empty($id) && !empty($taglist)) {
+				$feeditem = Item::selectFirst(['uri-id'], ['id' => $id]);
+				foreach ($taglist as $tag) {
+					Tag::store($feeditem['uri-id'], Tag::HASHTAG, $tag);
 				}
 			}
 		}
diff --git a/src/Worker/Cron.php b/src/Worker/Cron.php
index 2c264f0746..9ce00fb936 100644
--- a/src/Worker/Cron.php
+++ b/src/Worker/Cron.php
@@ -181,7 +181,7 @@ class Cron
 	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 */
 	private static function pollContacts() {
-		$min_poll_interval = DI::config()->get('system', 'min_poll_interval', 1);
+		$min_poll_interval = DI::config()->get('system', 'min_poll_interval');
 
 		Addon::reload();
 
diff --git a/src/Worker/OnePoll.php b/src/Worker/OnePoll.php
index 00d5694db3..4dfbf7cadb 100644
--- a/src/Worker/OnePoll.php
+++ b/src/Worker/OnePoll.php
@@ -60,7 +60,7 @@ class OnePoll
 			return;
 		}
 
-		if (($contact['network'] != Protocol::MAIL) || $force) {
+		if (($contact['network'] != Protocol::MAIL) && $force) {
 			Contact::updateFromProbe($contact_id);
 		}
 
diff --git a/static/defaults.config.php b/static/defaults.config.php
index 8111a68f1a..5e5b48c683 100644
--- a/static/defaults.config.php
+++ b/static/defaults.config.php
@@ -331,7 +331,7 @@ return [
 
 		// min_poll_interval (Integer)
 		// minimal distance in minutes between two polls for a contact. Reasonable values are between 1 and 59.
-		'min_poll_interval' => 1,
+		'min_poll_interval' => 15,
 
 		// no_count (Boolean)
 		// Don't do count calculations (currently only when showing photo albums).