diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 37d4c5a58b..cf030c2f87 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -13,12 +13,12 @@ jobs:
     strategy:
       matrix:
         php-versions: [7.3, 7.4]
-        nextcloud-versions: ['stable20', 'stable21', 'stable22']
+        nextcloud-versions: ['stable20', 'stable21', 'stable22', 'stable23']
         include:
             - php-versions: 7.4
-              nextcloud-versions: master
+              nextcloud-versions: stable24
             - php-versions: 8.0
-              nextcloud-versions: master
+              nextcloud-versions: stable24
     name: Nextcloud ${{ matrix.nextcloud-versions }} php${{ matrix.php-versions }} unit tests
     steps:
     - name: Set up php${{ matrix.php-versions }}
@@ -52,6 +52,7 @@ jobs:
       uses: codecov/codecov-action@v2.1.0
       if: ${{ always() && matrix.nextcloud-versions == 'master' }}
       with:
+        token: ${{ secrets.CODECOV_TOKEN }}
         file: ./nextcloud/apps/mail/tests/clover.unit.xml
         flags: unittests
         fail_ci_if_error: true
@@ -61,7 +62,7 @@ jobs:
       strategy:
           matrix:
               php-versions: [7.4, 8.0]
-              nextcloud-versions: ['master']
+              nextcloud-versions: ['stable24']
               db: ['sqlite', 'mysql', 'pgsql']
       name: php${{ matrix.php-versions }}-${{ matrix.db }} integration tests
       services:
@@ -91,7 +92,7 @@ jobs:
                   --health-timeout=5s
                   --health-retries=3
           postgres-service:
-              image: postgres
+              image: postgres:14
               env:
                   POSTGRES_USER: nextcloud
                   POSTGRES_DB: nextcloud
@@ -143,6 +144,7 @@ jobs:
             uses: codecov/codecov-action@v2.1.0
             if: ${{ always() && matrix.db == 'mysql' }}
             with:
+              token: ${{ secrets.CODECOV_TOKEN }}
               file: ./nextcloud/apps/mail/tests/clover.integration.xml
               flags: integrationtests
               fail_ci_if_error: true
diff --git a/lib/Service/AutoConfig/IspDb.php b/lib/Service/AutoConfig/IspDb.php
index 434f3fc800..70072959af 100644
--- a/lib/Service/AutoConfig/IspDb.php
+++ b/lib/Service/AutoConfig/IspDb.php
@@ -50,7 +50,8 @@ public function getUrls(): array {
 		];
 	}
 
-	public function __construct(IClientService $clientService, LoggerInterface $logger) {
+	public function __construct(IClientService $clientService,
+		LoggerInterface $logger) {
 		$this->client = $clientService->newClient();
 		$this->logger = $logger;
 	}
@@ -113,10 +114,9 @@ private function convertServerElement(\SimpleXMLElement $server): array {
 
 	/**
 	 * @param string $domain
-	 * @param bool $tryMx
 	 * @return array
 	 */
-	public function query(string $domain, string $email, bool $tryMx = true): array {
+	public function query(string $domain, string $email): array {
 		$this->logger->debug("IsbDb: querying <$domain>");
 		if (strpos($domain, '@') !== false) {
 			// TODO: use horde mail address parsing instead
@@ -143,14 +143,6 @@ public function query(string $domain, string $email, bool $tryMx = true): array
 				}
 			}
 		}
-
-		if ($tryMx && ($dns = dns_get_record($domain, DNS_MX))) {
-			$domain = $dns[0]['target'];
-			if (!($provider = $this->query($domain, $email, false))) {
-				[, $domain] = explode('.', $domain, 2);
-				$provider = $this->query($domain, $email, false);
-			}
-		}
 		return $provider;
 	}
 }