diff --git a/api.php b/api.php
index 505e160..373fc48 100644
--- a/api.php
+++ b/api.php
@@ -2075,6 +2075,7 @@ switch ($action) {
         $id = $input['id'] ?? '';
         $body = trim($input['body'] ?? '');
         $replyMailboxId = $input['mailbox_id'] ?? '';
+        $replyTo = trim($input['to'] ?? '');
         $replyCc = trim($input['cc'] ?? '');
         if (empty($body)) {
             http_response_code(400);
@@ -2124,7 +2125,8 @@ switch ($action) {
                 $ccToSend = $replyCc !== '' ? $replyCc : ($t['cc'] ?? '');
 
                 $subject = 'Re: ' . $t['subject'];
-                $sent = sendTicketMail($t['from_email'], $subject, $emailBody, $lastMsgId, trim($allRefs), $replyMailbox, $ccToSend);
+                $toAddress = $replyTo !== '' ? $replyTo : $t['from_email'];
+                $sent = sendTicketMail($toAddress, $subject, $emailBody, $lastMsgId, trim($allRefs), $replyMailbox, $ccToSend);
 
                 if (!$sent) {
                     http_response_code(500);
diff --git a/index.html b/index.html
index 813b355..28b0c79 100644
--- a/index.html
+++ b/index.html
@@ -452,6 +452,10 @@
                                     <label style="font-size:0.8rem;color:#888;min-width:60px;">Lähettäjä:</label>
                                     <select id="reply-mailbox-select" style="flex:1;padding:5px 10px;border:1px solid #ddd;border-radius:6px;font-size:0.85rem;"></select>
                                 </div>
+                                <div style="display:flex;align-items:center;gap:0.5rem;">
+                                    <label style="font-size:0.8rem;color:#888;min-width:60px;">Vast.ott.:</label>
+                                    <input type="text" id="reply-to" style="flex:1;padding:5px 10px;border:1px solid #ddd;border-radius:6px;font-size:0.85rem;">
+                                </div>
                                 <div style="display:flex;align-items:center;gap:0.5rem;">
                                     <label style="font-size:0.8rem;color:#888;min-width:60px;">CC:</label>
                                     <input type="text" id="reply-cc" placeholder="email1@example.com, email2@example.com" style="flex:1;padding:5px 10px;border:1px solid #ddd;border-radius:6px;font-size:0.85rem;">
diff --git a/script.js b/script.js
index e9a858d..b120d9c 100644
--- a/script.js
+++ b/script.js
@@ -1579,6 +1579,10 @@ async function showTicketDetail(id, companyId = '') {
         document.querySelector('.btn-reply-tab[data-reply-type="reply"]').classList.add('active');
         document.getElementById('btn-send-reply').textContent = 'Lähetä vastaus';
 
+        // TO-kenttä — tiketin alkuperäinen lähettäjä
+        const toField = document.getElementById('reply-to');
+        if (toField) toField.value = ticket.from_email || '';
+
         // CC-kenttä — täytetään tiketin CC:stä
         const ccField = document.getElementById('reply-cc');
         if (ccField) ccField.value = ticket.cc || '';
@@ -1709,9 +1713,11 @@ document.getElementById('btn-send-reply').addEventListener('click', async () =>
         const payload = { id: currentTicketId, body };
         if (ticketReplyType !== 'note') {
             const mbSel = document.getElementById('reply-mailbox-select');
+            const toFld = document.getElementById('reply-to');
             const ccFld = document.getElementById('reply-cc');
             const useSig = document.getElementById('reply-use-signature');
             if (mbSel) payload.mailbox_id = mbSel.value;
+            if (toFld && toFld.value.trim()) payload.to = toFld.value.trim();
             if (ccFld) payload.cc = ccFld.value.trim();
             if (useSig && !useSig.checked) payload.no_signature = true;
         }