diff --git a/tests/Sync/Sync/EmailITipTest.php b/tests/Sync/Sync/EmailITipTest.php
new file mode 100644
index 0000000..ec78332
--- /dev/null
+++ b/tests/Sync/Sync/EmailITipTest.php
@@ -0,0 +1,81 @@
+<?php
+
+namespace Tests\Sync\Sync;
+
+class EmailITipTest extends \Tests\SyncTestCase
+{
+    /**
+     * Test Sync with invalid itip
+     */
+    public function testSyncWithInvalidITip()
+    {
+        $this->emptyTestFolder('INBOX', 'mail');
+        $this->registerDevice();
+
+        // Test INBOX
+        $folderId = '38b950ebd62cd9a66929c89615d0fc04';
+        $syncKey = 0;
+        $request = <<<EOF
+            <?xml version="1.0" encoding="utf-8"?>
+            <!DOCTYPE AirSync PUBLIC "-//AIRSYNC//DTD AirSync//EN" "http://www.microsoft.com/">
+            <Sync xmlns="uri:AirSync">
+                <Collections>
+                    <Collection>
+                        <SyncKey>{$syncKey}</SyncKey>
+                        <CollectionId>{$folderId}</CollectionId>
+                    </Collection>
+                </Collections>
+            </Sync>
+            EOF;
+
+        $response = $this->request($request, 'Sync');
+        $this->assertEquals(200, $response->getStatusCode());
+        $syncKey++;
+
+        // Append messages
+        $this->appendMail('INBOX', 'mail.itip1');
+        $this->appendMail('INBOX', 'mail.itip.invalid');
+        $this->appendMail('INBOX', 'mail.sync2');
+
+        // Test that the synchornization works with the invalid itip in the middle
+        $request = <<<EOF
+            <?xml version="1.0" encoding="utf-8"?>
+            <!DOCTYPE AirSync PUBLIC "-//AIRSYNC//DTD AirSync//EN" "http://www.microsoft.com/">
+            <Sync xmlns="uri:AirSync" xmlns:AirSyncBase="uri:AirSyncBase">
+                <Collections>
+                    <Collection>
+                        <SyncKey>{$syncKey}</SyncKey>
+                        <CollectionId>{$folderId}</CollectionId>
+                        <DeletesAsMoves>1</DeletesAsMoves>
+                        <GetChanges>1</GetChanges>
+                        <Options>
+                            <FilterType>0</FilterType>
+                            <Conflict>1</Conflict>
+                            <BodyPreference xmlns="uri:AirSyncBase">
+                                <Type>2</Type>
+                                <TruncationSize>51200</TruncationSize>
+                                <AllOrNone>0</AllOrNone>
+                            </BodyPreference>
+                        </Options>
+                    </Collection>
+                </Collections>
+            </Sync>
+            EOF;
+
+        $response = $this->request($request, 'Sync');
+
+        $this->assertEquals(200, $response->getStatusCode());
+
+        $dom = $this->fromWbxml($response->getBody());
+        $xpath = $this->xpath($dom);
+
+        // print($dom->saveXML());
+
+        $root = "//ns:Sync/ns:Collections/ns:Collection";
+        $this->assertSame('1', $xpath->query("{$root}/ns:Status")->item(0)->nodeValue);
+        $this->assertSame(strval(++$syncKey), $xpath->query("{$root}/ns:SyncKey")->item(0)->nodeValue);
+        $this->assertSame($folderId, $xpath->query("{$root}/ns:CollectionId")->item(0)->nodeValue);
+        // We expect all three messages to synchronize, even if we fail to parse the invitation in the middle
+        $this->assertSame(3, $xpath->query("{$root}/ns:Commands/ns:Add")->count());
+    }
+}
diff --git a/tests/src/mail.itip.invalid b/tests/src/mail.itip.invalid
new file mode 100644
index 0000000..cace895
--- /dev/null
+++ b/tests/src/mail.itip.invalid
@@ -0,0 +1,51 @@
+MIME-Version: 1.0
+Date: Thu, 07 Dec 2023 13:29:14 +0100
+Message-ID: <14ab307198d32cee00b38ffb54c9e577@nestle.kolab.ch>
+From: "Organizer" <$from>
+To: <$to>
+Subject: Invalid itip invitation
+Content-Type: multipart/alternative;
+ boundary="=_f39ac9438326f676a8d562e163aa31e0"
+
+--=_f39ac9438326f676a8d562e163aa31e0
+Content-Transfer-Encoding: quoted-printable
+Content-Type: text/plain; charset=UTF-8;
+ format=flowed
+
+*Test*
+--=_f39ac9438326f676a8d562e163aa31e0
+Content-Transfer-Encoding: 8bit
+Content-Type: text/calendar; charset=UTF-8; method=REQUEST; name=event.ics
+
+BEGIN:VCALENDAR
+VERSION:2.0
+PRODID:-//Roundcube 1.5-git//Sabre VObject 4.5.3//EN
+CALSCALE:GREGORIAN
+METHOD:REQUEST
+BEGIN:VTIMEZONE
+TZID:Europe/Warsaw
+BEGIN:DAYLIGHT
+DTSTART:20230326T010000
+TZOFFSETFROM:+0100
+TZOFFSETTO:+0200
+TZNAME:CEST
+END:DAYLIGHT
+BEGIN:DAYLIGHT
+DTSTART:20240331T010000
+TZOFFSETFROM:+0100
+TZOFFSETTO:+0200
+TZNAME:CEST
+END:DAYLIGHT
+BEGIN:STANDARD
+DTSTART:20231029T010000
+TZOFFSETFROM:+0200
+TZOFFSETTO:+0100
+TZNAME:CET
+END:STANDARD
+END:VTIMEZONE
+BEGIN:VEVENT
+DTSTART;TZID=Europe/Warsaw:20231207T140000
+END:VEVENT
+END:VCALENDAR
+
+--=_f39ac9438326f676a8d562e163aa31e0--