diff --git a/public/categories/index.html b/public/categories/index.html
index d00c2ad..e9ccc5f 100755
--- a/public/categories/index.html
+++ b/public/categories/index.html
@@ -137,14 +137,14 @@
                 
               
               <li class="navigation-item">
-                <a href="/ru/categories/">🇷🇺</a>
+                <a href="/de/categories/">🇩🇪</a>
               </li>
             
           
             
               
               <li class="navigation-item">
-                <a href="/de/categories/">🇩🇪</a>
+                <a href="/ru/categories/">🇷🇺</a>
               </li>
             
           
diff --git a/public/de/404.html b/public/de/404.html
index 8caee7c..37a9928 100755
--- a/public/de/404.html
+++ b/public/de/404.html
@@ -136,14 +136,14 @@
                 
               
               <li class="navigation-item">
-                <a href="/ru/404.html">🇷🇺</a>
+                <a href="/404.html">🇬🇧</a>
               </li>
             
           
             
               
               <li class="navigation-item">
-                <a href="/404.html">🇬🇧</a>
+                <a href="/ru/404.html">🇷🇺</a>
               </li>
             
           
diff --git a/public/de/sitemap.xml b/public/de/sitemap.xml
index 3ce8530..a78d503 100755
--- a/public/de/sitemap.xml
+++ b/public/de/sitemap.xml
@@ -20,6 +20,11 @@
                 />
   </url><url>
     <loc>http://markinstefan.xyz/de/categories/</loc>
+    <xhtml:link
+                rel="alternate"
+                hreflang="de"
+                href="http://markinstefan.xyz/de/categories/"
+                />
     <xhtml:link
                 rel="alternate"
                 hreflang="en"
@@ -30,11 +35,6 @@
                 hreflang="ru"
                 href="http://markinstefan.xyz/ru/categories/"
                 />
-    <xhtml:link
-                rel="alternate"
-                hreflang="de"
-                href="http://markinstefan.xyz/de/categories/"
-                />
   </url><url>
     <loc>http://markinstefan.xyz/de/hochzeit/</loc>
     <xhtml:link
diff --git a/public/en/sitemap.xml b/public/en/sitemap.xml
index b13ae95..cbbfc62 100755
--- a/public/en/sitemap.xml
+++ b/public/en/sitemap.xml
@@ -20,6 +20,11 @@
                 />
   </url><url>
     <loc>http://markinstefan.xyz/categories/</loc>
+    <xhtml:link
+                rel="alternate"
+                hreflang="de"
+                href="http://markinstefan.xyz/de/categories/"
+                />
     <xhtml:link
                 rel="alternate"
                 hreflang="en"
@@ -30,11 +35,6 @@
                 hreflang="ru"
                 href="http://markinstefan.xyz/ru/categories/"
                 />
-    <xhtml:link
-                rel="alternate"
-                hreflang="de"
-                href="http://markinstefan.xyz/de/categories/"
-                />
   </url><url>
     <loc>http://markinstefan.xyz/contact/</loc>
     <xhtml:link
@@ -139,11 +139,6 @@
                 />
   </url><url>
     <loc>http://markinstefan.xyz/tags/</loc>
-    <xhtml:link
-                rel="alternate"
-                hreflang="ru"
-                href="http://markinstefan.xyz/ru/tags/"
-                />
     <xhtml:link
                 rel="alternate"
                 hreflang="de"
@@ -154,5 +149,10 @@
                 hreflang="en"
                 href="http://markinstefan.xyz/tags/"
                 />
+    <xhtml:link
+                rel="alternate"
+                hreflang="ru"
+                href="http://markinstefan.xyz/ru/tags/"
+                />
   </url>
 </urlset>
diff --git a/public/rsvp-submit.php b/public/rsvp-submit.php
index 88c3851..2219ab5 100755
--- a/public/rsvp-submit.php
+++ b/public/rsvp-submit.php
@@ -1,6 +1,5 @@
 <?php
 
-
 require __DIR__ . '/vendor/autoload.php';
 
 use PHPMailer\PHPMailer\PHPMailer;
@@ -10,7 +9,6 @@ use Dotenv\Dotenv;
 $dotenv = Dotenv::createImmutable(__DIR__ . '/../');
 $dotenv->safeLoad();
 
-
 function checkboxArrayToString($value)
 {
     if (is_array($value) && count($value) > 0) {
@@ -39,8 +37,8 @@ $first_name = trim($_POST['first_name'] ?? '');
 $last_name  = trim($_POST['last_name'] ?? '');
 $name       = trim("$first_name $last_name");
 
-$email      = trim($_POST['email'] ?? '');
-$phone      = trim($_POST['phone'] ?? '');
+$email = trim($_POST['email'] ?? '');
+$phone = trim($_POST['phone'] ?? '');
 
 // Attendance
 $attendance = $_POST['attendance'] ?? 'Unknown';
@@ -107,12 +105,13 @@ try {
     $mail->CharSet = 'UTF-8';
 
     $mail->isSMTP();
-    $mail->Host = gethostbyname($_ENV['SMTP_HOST']);
+    $mail->Host       = $_ENV['SMTP_HOST'];
     $mail->SMTPAuth   = true;
     $mail->Username   = $_ENV['SMTP_USER'];
     $mail->Password   = $_ENV['SMTP_PASS'];
     $mail->SMTPSecure = PHPMailer::ENCRYPTION_STARTTLS;
     $mail->Port       = (int)$_ENV['SMTP_PORT'];
+    $mail->Timeout    = 10;
 
     $mail->setFrom($_ENV['FROM_EMAIL'], $_ENV['FROM_NAME']);
     $mail->addAddress($_ENV['TO_EMAIL']);
@@ -196,7 +195,6 @@ EOD;
 
     $mail->Body = $body;
 
-$mail->Timeout = 10;
     $mail->send();
 
     header('Location: /thank-you/');
@@ -204,5 +202,8 @@ $mail->Timeout = 10;
 
 } catch (Exception $e) {
 
-    echo "RSVP could not be sent. Mailer Error: {$mail->ErrorInfo}";
+    error_log('RSVP mail error: ' . $mail->ErrorInfo);
+
+    http_response_code(500);
+    echo 'An error occurred while sending the RSVP.';
 }
diff --git a/public/ru/categories/index.html b/public/ru/categories/index.html
index fdd3de6..90c5031 100755
--- a/public/ru/categories/index.html
+++ b/public/ru/categories/index.html
@@ -137,14 +137,14 @@
                 
               
               <li class="navigation-item">
-                <a href="/categories/">🇬🇧</a>
+                <a href="/de/categories/">🇩🇪</a>
               </li>
             
           
             
               
               <li class="navigation-item">
-                <a href="/de/categories/">🇩🇪</a>
+                <a href="/categories/">🇬🇧</a>
               </li>
             
           
diff --git a/public/ru/index.html b/public/ru/index.html
index 8266e40..a76c1ac 100755
--- a/public/ru/index.html
+++ b/public/ru/index.html
@@ -138,14 +138,14 @@
                 
               
               <li class="navigation-item">
-                <a href="/">🇬🇧</a>
+                <a href="/de/">🇩🇪</a>
               </li>
             
           
             
               
               <li class="navigation-item">
-                <a href="/de/">🇩🇪</a>
+                <a href="/">🇬🇧</a>
               </li>
             
           
diff --git a/public/ru/series/index.html b/public/ru/series/index.html
index cee8a31..6dbfdab 100755
--- a/public/ru/series/index.html
+++ b/public/ru/series/index.html
@@ -137,14 +137,14 @@
                 
               
               <li class="navigation-item">
-                <a href="/de/series/">🇩🇪</a>
+                <a href="/series/">🇬🇧</a>
               </li>
             
           
             
               
               <li class="navigation-item">
-                <a href="/series/">🇬🇧</a>
+                <a href="/de/series/">🇩🇪</a>
               </li>
             
           
diff --git a/public/ru/sitemap.xml b/public/ru/sitemap.xml
index acdf2e8..685feae 100755
--- a/public/ru/sitemap.xml
+++ b/public/ru/sitemap.xml
@@ -20,6 +20,11 @@
                 />
   </url><url>
     <loc>http://markinstefan.xyz/ru/categories/</loc>
+    <xhtml:link
+                rel="alternate"
+                hreflang="de"
+                href="http://markinstefan.xyz/de/categories/"
+                />
     <xhtml:link
                 rel="alternate"
                 hreflang="en"
@@ -30,18 +35,8 @@
                 hreflang="ru"
                 href="http://markinstefan.xyz/ru/categories/"
                 />
-    <xhtml:link
-                rel="alternate"
-                hreflang="de"
-                href="http://markinstefan.xyz/de/categories/"
-                />
   </url><url>
     <loc>http://markinstefan.xyz/ru/series/</loc>
-    <xhtml:link
-                rel="alternate"
-                hreflang="de"
-                href="http://markinstefan.xyz/de/series/"
-                />
     <xhtml:link
                 rel="alternate"
                 hreflang="en"
@@ -52,13 +47,13 @@
                 hreflang="ru"
                 href="http://markinstefan.xyz/ru/series/"
                 />
-  </url><url>
-    <loc>http://markinstefan.xyz/ru/tags/</loc>
     <xhtml:link
                 rel="alternate"
-                hreflang="ru"
-                href="http://markinstefan.xyz/ru/tags/"
+                hreflang="de"
+                href="http://markinstefan.xyz/de/series/"
                 />
+  </url><url>
+    <loc>http://markinstefan.xyz/ru/tags/</loc>
     <xhtml:link
                 rel="alternate"
                 hreflang="de"
@@ -69,6 +64,11 @@
                 hreflang="en"
                 href="http://markinstefan.xyz/tags/"
                 />
+    <xhtml:link
+                rel="alternate"
+                hreflang="ru"
+                href="http://markinstefan.xyz/ru/tags/"
+                />
   </url><url>
     <loc>http://markinstefan.xyz/ru/contact/</loc>
     <xhtml:link
@@ -90,13 +90,13 @@
     <loc>http://markinstefan.xyz/ru/</loc>
     <xhtml:link
                 rel="alternate"
-                hreflang="en"
-                href="http://markinstefan.xyz/"
+                hreflang="de"
+                href="http://markinstefan.xyz/de/"
                 />
     <xhtml:link
                 rel="alternate"
-                hreflang="de"
-                href="http://markinstefan.xyz/de/"
+                hreflang="en"
+                href="http://markinstefan.xyz/"
                 />
     <xhtml:link
                 rel="alternate"
diff --git a/public/tags/index.html b/public/tags/index.html
index 89eaf1f..94fd14a 100755
--- a/public/tags/index.html
+++ b/public/tags/index.html
@@ -137,14 +137,14 @@
                 
               
               <li class="navigation-item">
-                <a href="/ru/tags/">🇷🇺</a>
+                <a href="/de/tags/">🇩🇪</a>
               </li>
             
           
             
               
               <li class="navigation-item">
-                <a href="/de/tags/">🇩🇪</a>
+                <a href="/ru/tags/">🇷🇺</a>
               </li>
             
           
diff --git a/static/rsvp-submit.php b/static/rsvp-submit.php
index 88c3851..2219ab5 100755
--- a/static/rsvp-submit.php
+++ b/static/rsvp-submit.php
@@ -1,6 +1,5 @@
 <?php
 
-
 require __DIR__ . '/vendor/autoload.php';
 
 use PHPMailer\PHPMailer\PHPMailer;
@@ -10,7 +9,6 @@ use Dotenv\Dotenv;
 $dotenv = Dotenv::createImmutable(__DIR__ . '/../');
 $dotenv->safeLoad();
 
-
 function checkboxArrayToString($value)
 {
     if (is_array($value) && count($value) > 0) {
@@ -39,8 +37,8 @@ $first_name = trim($_POST['first_name'] ?? '');
 $last_name  = trim($_POST['last_name'] ?? '');
 $name       = trim("$first_name $last_name");
 
-$email      = trim($_POST['email'] ?? '');
-$phone      = trim($_POST['phone'] ?? '');
+$email = trim($_POST['email'] ?? '');
+$phone = trim($_POST['phone'] ?? '');
 
 // Attendance
 $attendance = $_POST['attendance'] ?? 'Unknown';
@@ -107,12 +105,13 @@ try {
     $mail->CharSet = 'UTF-8';
 
     $mail->isSMTP();
-    $mail->Host = gethostbyname($_ENV['SMTP_HOST']);
+    $mail->Host       = $_ENV['SMTP_HOST'];
     $mail->SMTPAuth   = true;
     $mail->Username   = $_ENV['SMTP_USER'];
     $mail->Password   = $_ENV['SMTP_PASS'];
     $mail->SMTPSecure = PHPMailer::ENCRYPTION_STARTTLS;
     $mail->Port       = (int)$_ENV['SMTP_PORT'];
+    $mail->Timeout    = 10;
 
     $mail->setFrom($_ENV['FROM_EMAIL'], $_ENV['FROM_NAME']);
     $mail->addAddress($_ENV['TO_EMAIL']);
@@ -196,7 +195,6 @@ EOD;
 
     $mail->Body = $body;
 
-$mail->Timeout = 10;
     $mail->send();
 
     header('Location: /thank-you/');
@@ -204,5 +202,8 @@ $mail->Timeout = 10;
 
 } catch (Exception $e) {
 
-    echo "RSVP could not be sent. Mailer Error: {$mail->ErrorInfo}";
+    error_log('RSVP mail error: ' . $mail->ErrorInfo);
+
+    http_response_code(500);
+    echo 'An error occurred while sending the RSVP.';
 }