diff --git a/DeskHub-Webseite/includes/mail_text.php b/DeskHub-Webseite/includes/mail_text.php
new file mode 100644
index 00000000..0ccd1d41
--- /dev/null
+++ b/DeskHub-Webseite/includes/mail_text.php
@@ -0,0 +1,170 @@
+]+charset[^>]*>/i', '', $html) ?? $html;
+ $prev = libxml_use_internal_errors(true);
+ $dom = new DOMDocument();
+ $ok = $dom->loadHTML('' . $html, LIBXML_NOWARNING | LIBXML_NOERROR | LIBXML_NONET);
+ libxml_clear_errors();
+ libxml_use_internal_errors($prev);
+ if (!$ok || !$dom->documentElement) return mail_html_to_text_regex($html);
+
+ $blocks = ['p', 'div', 'section', 'article', 'header', 'footer', 'table', 'tr', 'ul', 'ol', 'blockquote', 'pre', 'h1', 'h2', 'h3', 'h4', 'h5', 'h6', 'hr', 'address', 'center', 'form', 'dl', 'dt', 'dd'];
+ $skip = ['script', 'style', 'head', 'title', 'noscript', 'template', 'meta', 'link', 'svg', 'object', 'embed', 'iframe', 'canvas', 'map'];
+ $out = '';
+ // Zeilenwechsel für Blöcke und Listen: nie doppelt hintereinander (ein
dagegen erzeugt immer einen)
+ $newline = function () use (&$out): void {
+ if ($out !== '' && !str_ends_with(rtrim($out, ' '), "
+")) $out = rtrim($out, ' ') . "
+";
+ };
+ $walk = function (DOMNode $node) use (&$walk, &$out, $blocks, $skip, $newline): void {
+ foreach ($node->childNodes as $child) {
+ if ($child instanceof DOMText) {
+ // Umbrüche und Einrückung im Quelltext sind keine Zeilenwechsel
+ $out .= preg_replace('/[ \t\r\n\f]+/', ' ', $child->nodeValue ?? '');
+ } elseif ($child instanceof DOMElement) {
+ $tag = strtolower($child->tagName);
+ if (in_array($tag, $skip, true)) continue;
+ if ($child->hasAttribute('hidden') || mail_style_hides($child->getAttribute('style'))) continue;
+ if ($tag === 'br') { $out .= "\n"; continue; }
+ if ($tag === 'img') { $alt = trim($child->getAttribute('alt')); if ($alt !== '') $out .= ' ' . $alt . ' '; continue; }
+ $block = in_array($tag, $blocks, true);
+ if ($block) $newline();
+ if ($tag === 'li') { $newline(); $out .= '• '; }
+ if ($tag === 'td' || $tag === 'th') $out .= ' ';
+ $walk($child);
+ if ($tag === 'td' || $tag === 'th') $out .= ' ';
+ if ($block || $tag === 'li') $newline();
+ }
+ }
+ };
+ $walk($dom->documentElement);
+ return $out;
+}
+
+function mail_html_to_text_regex(string $html): string
+{
+ $html = preg_replace('~~s', '', $html) ?? $html;
+ $html = preg_replace('~<(script|style|head|title|noscript|template)\b[^>]*>.*?~is', '', $html) ?? $html;
+ $html = preg_replace('~~i', "\n", $html) ?? $html;
+ $html = preg_replace('~~i', "\n", $html) ?? $html;
+ $html = preg_replace('~]*>~i', "\n• ", $html) ?? $html;
+ return html_entity_decode(strip_tags($html), ENT_QUOTES | ENT_HTML5, 'UTF-8');
+}
+
+/** Räumt Text auf: unsichtbare Zeichen, geschützte Leerzeichen, überzählige Leerzeilen. */
+function mail_clean_text(string $text): string
+{
+ $text = str_replace(["\r\n", "\r"], "\n", $text);
+ $text = str_replace("\u{00A0}", ' ', $text);
+ $text = preg_replace('/[' . preg_quote(MAIL_INVISIBLE_CHARS, '/') . ']+/u', '', $text) ?? $text;
+ $lines = [];
+ foreach (explode("\n", $text) as $line) {
+ $lines[] = trim(preg_replace('/[ \t]{2,}/', ' ', $line) ?? $line);
+ }
+ $text = implode("\n", $lines);
+ $text = preg_replace("/\n{3,}/", "\n\n", $text) ?? $text;
+ return trim($text);
+}
+
+/** Dekodiert den Inhalt eines Mail-Teils (Transferkodierung und Zeichensatz) nach UTF-8. */
+function mail_decode_part(string $raw, int $encoding, string $charset): string
+{
+ $data = match ($encoding) {
+ 3 => (string) base64_decode(preg_replace('/\s+/', '', $raw) ?? $raw, false),
+ 4 => quoted_printable_decode($raw),
+ default => $raw,
+ };
+ $charset = strtolower(trim($charset));
+ if ($charset === '' || $charset === 'utf-8' || $charset === 'utf8' || $charset === 'us-ascii') {
+ return mb_check_encoding($data, 'UTF-8') ? $data : (string) mb_convert_encoding($data, 'UTF-8', 'ISO-8859-1');
+ }
+ try {
+ return (string) mb_convert_encoding($data, 'UTF-8', $charset);
+ } catch (Throwable) {
+ return mb_check_encoding($data, 'UTF-8') ? $data : (string) mb_convert_encoding($data, 'UTF-8', 'ISO-8859-1');
+ }
+}
+
+/**
+ * Sammelt die Text-Teile (text/plain, text/html) einer IMAP-Struktur, ohne Anhänge.
+ *
+ * @return array
+ */
+function mail_collect_text_parts(object $part, string $no = ''): array
+{
+ $found = [];
+ $isMulti = !empty($part->parts) && is_array($part->parts);
+ if ($isMulti) {
+ foreach ($part->parts as $i => $sub) {
+ $found = array_merge($found, mail_collect_text_parts($sub, $no === '' ? (string) ($i + 1) : $no . '.' . ($i + 1)));
+ }
+ return $found;
+ }
+ // type 0 = text
+ if ((int) ($part->type ?? -1) !== 0) return [];
+ $disposition = strtolower((string) ($part->disposition ?? ''));
+ $charset = '';
+ $filename = false;
+ foreach (array_merge((array) ($part->parameters ?? []), (array) ($part->dparameters ?? [])) as $p) {
+ $attr = strtolower((string) ($p->attribute ?? ''));
+ if ($attr === 'charset') $charset = (string) $p->value;
+ if ($attr === 'name' || $attr === 'filename') $filename = true;
+ }
+ if ($disposition === 'attachment' || $filename) return [];
+ $found[] = ['no' => $no === '' ? '1' : $no, 'subtype' => strtoupper((string) ($part->subtype ?? 'PLAIN')), 'encoding' => (int) ($part->encoding ?? 0), 'charset' => $charset];
+ return $found;
+}
+
+/**
+ * Bester Text einer Mail: bevorzugt text/plain; ist der nur eine kurze Floskel ("Bitte HTML-Ansicht verwenden") und die HTML-Fassung
+ * deutlich länger, wird die HTML-Fassung als Text genommen.
+ *
+ * @param callable(string):string $fetchPart liefert den rohen Inhalt eines Teils (imap_fetchbody)
+ */
+function mail_best_text(object $structure, callable $fetchPart): string
+{
+ $plain = '';
+ $html = '';
+ $havePlain = false;
+ $haveHtml = false;
+ foreach (mail_collect_text_parts($structure) as $p) {
+ if ($p['subtype'] === 'PLAIN' && !$havePlain) {
+ $plain = mail_clean_text(mail_decode_part($fetchPart($p['no']), $p['encoding'], $p['charset']));
+ $havePlain = true;
+ } elseif ($p['subtype'] === 'HTML' && !$haveHtml) {
+ $html = mail_html_to_text(mail_decode_part($fetchPart($p['no']), $p['encoding'], $p['charset']));
+ $haveHtml = true;
+ }
+ }
+ if ($plain !== '' && (mb_strlen($plain) >= 40 || $html === '' || mb_strlen($html) <= mb_strlen($plain) * 2)) return $plain;
+ return $html !== '' ? $html : $plain;
+}