diff --git a/index.html b/index.html
index 3123831..cf22f11 100644
--- a/index.html
+++ b/index.html
@@ -109,9 +109,6 @@
         <label for="nospam" class="pure-checkbox">
             <input id="nospam" type="checkbox"/> Avoid spamming
         </label>
-        <label for="save" class="pure-checkbox">
-            <input id="save" type="checkbox" checked/> Save to file
-        </label>
         <label for="logs" class="pure-checkbox">
             <input id="logs" class="local-only" type="checkbox"/> Show logs
         </label>
@@ -190,7 +187,6 @@
 
 <script type="module">
 import { default as $, LogRecord, Rpc2 } from '/';
-if (performance.getEntriesByType('navigation')[0].type === 'reload') await Rpc2.invoke('exit');
 
 let limit = 0;
 let length = 0;
@@ -202,6 +198,13 @@ let writable = null;
 let filereader = null;
 let subcategories = [];
 
+window.addEventListener('beforeunload', (e) => {
+    writable?.abort().catch(() => void 0);
+    Rpc2.notify('exit');
+    e.preventDefault();
+    e.returnValue = '';
+});
+
 let { locales, mapping, parameters } = await Rpc2.invoke('context');
 let account = new String(parameters.account);
 let name = account.split('@', 1).pop();
@@ -229,7 +232,7 @@ async function handlePrimaryButtonClick() {
                 reader.readAsArrayBuffer(file);
             }));
 
-            let [file, buffer] = await filereader().catch(() => []);
+            let [file, buffer] = await filereader().catch(e => alert('(ERROR) ' + new String(e ?? 'Unable to read data')));
             writable = await handle.createWritable().catch(() => null);
             limit = await Rpc2.invoke('ready', file.name, new Uint8Array(buffer).toBase64());
             $.get('#fileLabel').innerText = file.name;
@@ -238,7 +241,7 @@ async function handlePrimaryButtonClick() {
             break;
         case 'READY':
             let locale = $('#locale').value;
-            let options = { locale, mapping: new Object()};
+            let options = { locale, mapping: new Object(), writable: new Boolean(writable) };
 
             for (let element of $.all("input[type='number'].params")) {
                 parameters[element.id] = element.disabled ? null : element.valueAsNumber;
diff --git a/main.py b/main.py
index 5370d31..ffa8c91 100644
--- a/main.py
+++ b/main.py
@@ -46,9 +46,9 @@ def main(driver: Chrome, logger = logging.getLogger('main')):
     class Status(Enum):
         IDLE = 0
         READY = 1
-        RUNNING = 3
-        STANDBY = 4
-        CLOSING = 5
+        RUNNING = 2
+        STANDBY = 3
+        CLOSING = 4
     
     class ColumnMapping:
         def __init__(self, email=None, recipient=None, code=None, region=None, sent=None, variables=None):
@@ -337,6 +337,17 @@ def main(driver: Chrome, logger = logging.getLogger('main')):
     sp.set('merge', merge)
     sp.set('progress', lambda: progress)
 
+    def save():
+        try:
+            file = Path('.').joinpath(filename or f'Mailer-{datetime.now().strftime('%Y%m%d-%H%M%S-%f')}.xlsx').resolve()
+            logger.info('Saving file at %s', str(file))
+            wb.save(file)
+        except Exception as e:
+            logger.error('Error while writing data to file', exc_info=e)
+
+    exit = sp.pop('exit')
+    sp.set('exit', lambda: (save() if options.get('writable') and status.value >= 2 else None, exit()))
+
     class MismatchedEmailSubject(Exception): pass
     class MismatchedEmailAddress(Exception): pass
 
@@ -553,7 +564,7 @@ def main(driver: Chrome, logger = logging.getLogger('main')):
                 status = Status.STANDBY
                 continue
 
-        if options.get('save'):
+        if options.get('writable'):
             try:
                 status = Status.CLOSING
                 flow.allow(Wait, False)
@@ -565,9 +576,8 @@ def main(driver: Chrome, logger = logging.getLogger('main')):
             except Close:
                 pass
             except Exception as e:
-                file = Path('.').joinpath(filename or f'Mailer-{datetime.now().strftime('%Y%m%d-%H%M%S-%f')}.xlsx').resolve()
-                logger.warning('RPC communication failed; saving at %s', str(file), exc_info=e)
-                wb.save(file)
+                logger.warning('RPC communication failed', exc_info=e)
+                save()
 
         flow.allow(Timeout, False)
         flow.allow(Close, False)
diff --git a/requirements.txt b/requirements.txt
index dae8a24..309abe7 100644
Binary files a/requirements.txt and b/requirements.txt differ