lucs7 · Oct 9, 2026
diff --git a/Pages/Export/CalendarExportDisplay.php b/Pages/Export/CalendarExportDisplay.php
@@ -1,5 +1,6 @@
 <?php
 
+use LibreBooking\Calendar\IcsMethod;
 use Sabre\VObject\Component\VAlarm;
 use Sabre\VObject\Component\VCalendar;
 use Sabre\VObject\Component\VEvent;
@@ -18,14 +19,16 @@ public function __construct()
     /**
      * @param iCalendarReservationView[] $reservations
      * @param string|null $calendarName Optional display name rendered as X-WR-CALNAME
+     * @param IcsMethod $method PUBLISH for feeds and exports. Emails send REQUEST, or CANCEL for deletions,
+     *                          with the default address as organizer and the recipient as the only attendee.
      */
-    public function Render(array $reservations, ?string $calendarName = null): string
+    public function Render(array $reservations, ?string $calendarName = null, IcsMethod $method = IcsMethod::PUBLISH): string
     {
         // Values passed as constructor children are merged over getDefaults(),
         // replacing the PRODID that VCalendar would otherwise generate.
         $vcal = new VCalendar([
             'PRODID' => '-//LibreBooking//NONSGML ' . Configuration::VERSION . '//EN',
-            'METHOD' => 'REQUEST',
+            'METHOD' => $method->value,
         ]);
 
         if ($calendarName !== null && $calendarName !== '') {
@@ -54,10 +57,18 @@ public function Render(array $reservations, ?string $calendarName = null): strin
             $event->add('DTEND', $res->DateEnd->Format($isoFormat));
             $event->add('LAST-MODIFIED', $res->LastModified->Format($isoFormat));
             $event->add('LOCATION', $res->Location);
-            $event->add('ORGANIZER', 'mailto:' . $res->OrganizerEmail, ['CN' => $res->Organizer]);
-            $event->add('STATUS', $res->IsPending ? 'TENTATIVE' : 'CONFIRMED');
+            if ($method !== IcsMethod::PUBLISH && !empty($res->OrganizerSentBy)) {
+                $event->add('ORGANIZER', 'mailto:' . $res->OrganizerSentBy, ['CN' => $res->SenderName]);
+            } elseif (!empty($res->OrganizerEmail)) {
+                $organizerParams = ['CN' => $res->Organizer];
+                if (!empty($res->OrganizerSentBy)) {
+                    // RFC 5545 §3.2.18: the site's address sends on the owner's behalf
+                    $organizerParams['SENT-BY'] = 'mailto:' . $res->OrganizerSentBy;
+                }
+                $event->add('ORGANIZER', 'mailto:' . $res->OrganizerEmail, $organizerParams);
+            }
+            $event->add('STATUS', $method === IcsMethod::CANCEL ? 'CANCELLED' : ($res->IsPending ? 'TENTATIVE' : 'CONFIRMED'));
             $event->add('SUMMARY', $res->Summary);
-            $event->add('SEQUENCE', 0);
             $event->add('URL', $res->ReservationUrl);
             $event->add('X-MICROSOFT-CDO-BUSYSTATUS', 'BUSY');
 
@@ -88,6 +99,17 @@ public function Render(array $reservations, ?string $calendarName = null): strin
                 }
             }
 
+            $attendeeEmail = $res->AttendeeEmail ?? $res->OrganizerEmail;
+            if ($method !== IcsMethod::PUBLISH && !empty($res->OrganizerSentBy) && !empty($attendeeEmail)) {
+                $attendeeName = $res->AttendeeEmail ? $res->AttendeeName : $res->Organizer;
+                $event->add('ATTENDEE', 'mailto:' . $attendeeEmail, array_filter([
+                    'CN' => $attendeeName,
+                    'ROLE' => 'REQ-PARTICIPANT',
+                    'PARTSTAT' => 'NEEDS-ACTION',
+                    'RSVP' => 'FALSE',
+                ]));
+            }
+
             if ($res->StartReminder !== null) {
                 $alarm = new VAlarm($vcal, 'VALARM');
                 $event->add($alarm);

diff --git a/lib/Application/Schedule/iCalendarReservationView.php b/lib/Application/Schedule/iCalendarReservationView.php
@@ -9,6 +9,10 @@ class iCalendarReservationView
     public $Description;
     public $Organizer;
     public $OrganizerEmail;
+    public $OrganizerSentBy;
+    public $SenderName;
+    public $AttendeeName;
+    public $AttendeeEmail;
     public $RecurRule;
     public $ReferenceNumber;
     public $Summary;
@@ -60,12 +64,6 @@ public function __construct($res, UserSession $currentUser, IPrivacyFilter $priv
         $this->ExportFactory = PluginManager::Instance()->LoadExport();
 
         $privateNotice = 'Private';
-        $privateEmail = Configuration::Instance()->GetKey(ConfigKeys::EMAIL_DEFAULT_FROM_ADDRESS);
-        static $missingPrivateOrganizerEmailLogged = false;
-        if (!$canViewUser && $privateEmail === '' && !$missingPrivateOrganizerEmailLogged) {
-            Log::Error('ICS private organizer email is not configured. Set the email.default.from.address setting.');
-            $missingPrivateOrganizerEmailLogged = true;
-        }
 
         $this->Classification = method_exists($this->ExportFactory, 'GetIcalendarClassification') ? $this->ExportFactory->GetIcalendarClassification($res) : 'PUBLIC';
         if ($res->DateCreated) {
@@ -78,9 +76,23 @@ public function __construct($res, UserSession $currentUser, IPrivacyFilter $priv
         $this->DateStart = $res->StartDate;
         $this->Summary = $canViewDetails ? $factory->Format($res, $summaryFormat) : $privateNotice;
         $this->Description = $canViewDetails ? ($res->Description ?? '') : $privateNotice;
-        $fullName = new FullName($res->OwnerFirstName, $res->OwnerLastName);
-        $this->Organizer = $canViewUser ? $fullName->__toString() : $privateNotice;
-        $this->OrganizerEmail = $canViewUser ? $res->OwnerEmailAddress : $privateEmail;
+
+        $defaultFromAddress = Configuration::Instance()->GetKey(ConfigKeys::EMAIL_DEFAULT_FROM_ADDRESS);
+        if ($canViewUser) {
+            $ownerName = new FullName($res->OwnerFirstName, $res->OwnerLastName);
+            $this->Organizer = $ownerName->__toString();
+            $this->OrganizerEmail = $res->OwnerEmailAddress;
+            $this->OrganizerSentBy = $defaultFromAddress;
+            $this->SenderName = Configuration::Instance()->GetKey(ConfigKeys::EMAIL_DEFAULT_FROM_NAME);
+        } else {
+            $this->Organizer = $privateNotice;
+            $this->OrganizerEmail = $defaultFromAddress;
+            static $missingPrivateOrganizerEmailLogged = false;
+            if ($defaultFromAddress === '' && !$missingPrivateOrganizerEmailLogged) {
+                Log::Error('ICS private organizer email is not configured. Set the email.default.from.address setting.');
+                $missingPrivateOrganizerEmailLogged = true;
+            }
+        }
         $this->RecurRule = $this->CreateRecurRule($res);
         $this->ReferenceNumber = $res->ReferenceNumber;
         $this->ReservationUrl = sprintf(
@@ -97,10 +109,6 @@ public function __construct($res, UserSession $currentUser, IPrivacyFilter $priv
         $this->LastModified = empty($res->ModifiedDate) || $res->ModifiedDate->ToString() == '' ? $this->DateCreated : $res->ModifiedDate;
         $this->IsPending = $res->RequiresApproval;
 
-        if ($canViewUser && $res->OwnerId == $currentUser->UserId) {
-            $this->OrganizerEmail = str_replace('@', '-noreply@', $res->OwnerEmailAddress);
-        }
-
         $this->ExtraIcalLines = method_exists($this->ExportFactory, 'GetIcalendarExtraLines') ? $this->ExportFactory->GetIcalendarExtraLines($res) : null;
     }
 

diff --git a/lib/Email/IEmailMessage.php b/lib/Email/IEmailMessage.php
@@ -46,7 +46,7 @@ public function ReplyTo();
      * @abstract
      * @param string $contents
      * @param string $fileName
-     * @param string|null $mimeType Full Content-Type value (e.g. 'text/calendar; method=REQUEST'). Null auto-detects from $fileName.
+     * @param string|null $mimeType Full Content-Type value (e.g. 'text/calendar; method=PUBLISH'). Null auto-detects from $fileName.
      */
     public function AddStringAttachment($contents, $fileName, ?string $mimeType = null);
 

diff --git a/lib/Email/Messages/ReservationDeletedEmail.php b/lib/Email/Messages/ReservationDeletedEmail.php
@@ -1,5 +1,7 @@
 <?php
 
+use LibreBooking\Calendar\IcsMethod;
+
 require_once(ROOT_DIR . 'lib/Email/Messages/ReservationEmailMessage.php');
 
 class ReservationDeletedEmail extends ReservationEmailMessage
@@ -25,4 +27,9 @@ protected function GetTemplateName()
     {
         return 'ReservationDeleted.tpl';
     }
+
+    protected function GetIcsMethod(): IcsMethod
+    {
+        return IcsMethod::CANCEL;
+    }
 }
diff --git a/lib/Email/Messages/ReservationEmailMessage.php b/lib/Email/Messages/ReservationEmailMessage.php
@@ -1,5 +1,7 @@
 <?php
 
+use LibreBooking\Calendar\IcsMethod;
+
 require_once(ROOT_DIR . 'lib/Email/namespace.php');
 require_once(ROOT_DIR . 'Pages/Pages.php');
 require_once(ROOT_DIR . 'Pages/Export/CalendarExportDisplay.php');
@@ -215,14 +217,33 @@ protected function PopulateIcsAttachment($currentInstance, $attributeValues)
         $rv->UserPreferences = $this->reservationOwner->GetPreferences();
         $rv->OwnerEmailAddress = $this->reservationOwner->EmailAddress();
 
-        $icsView = new iCalendarReservationView($rv, $this->reservationSeries->BookedBy(), new NullPrivacyFilter());
+        // BookedBy() is null for series from ReservationRepository::BuildSeries(); use the
+        // owner, with a timezone for the {startdate}/{enddate} summary placeholders.
+        $currentUser = $this->reservationSeries->BookedBy();
+        if ($currentUser === null) {
+            $currentUser = new UserSession($this->reservationOwner->Id());
+            $currentUser->Timezone = $this->timezone;
+        }
+        $icsView = new iCalendarReservationView($rv, $currentUser, new NullPrivacyFilter());
+        // the attendee is whoever the email goes to: the owner, or an invitee, guest or share recipient
+        $recipient = $this->To();
+        $recipient = is_array($recipient) ? $recipient[0] : $recipient;
+        $icsView->AttendeeName = $recipient->Name();
+        $icsView->AttendeeEmail = $recipient->Address();
+
+        $method = $this->GetIcsMethod();
 
         $display = new CalendarExportDisplay();
-        $icsContents = $display->Render([$icsView]);
+        $icsContents = $display->Render([$icsView], null, $method);
         $this->AddStringAttachment(
             contents: $icsContents,
             fileName: 'reservation.ics',
-            mimeType: 'text/calendar; charset=UTF-8; method=REQUEST'
+            mimeType: "text/calendar; charset=UTF-8; method={$method->value}"
         );
     }
+
+    protected function GetIcsMethod(): IcsMethod
+    {
+        return IcsMethod::REQUEST;
+    }
 }
diff --git a/lib/Email/Messages/ReservationUpdatedEmail.php b/lib/Email/Messages/ReservationUpdatedEmail.php
@@ -6,7 +6,7 @@ class ReservationUpdatedEmail extends ReservationEmailMessage
 {
     public function Subject()
     {
-        return $this->Translate('ReservationUpdatedAdminSubjectWithResource', [$this->primaryResource->GetName()]);
+        return $this->Translate('ReservationUpdatedSubjectWithResource', [$this->primaryResource->GetName()]);
     }
 
     protected function GetTemplateName()

diff --git a/src/Calendar/IcsMethod.php b/src/Calendar/IcsMethod.php
@@ -0,0 +1,15 @@
+<?php
+
+declare(strict_types=1);
+
+namespace LibreBooking\Calendar;
+
+/**
+ * RFC 5546 iTip method for an ICS VCALENDAR.
+ */
+enum IcsMethod: string
+{
+    case PUBLISH = 'PUBLISH';
+    case REQUEST = 'REQUEST';
+    case CANCEL = 'CANCEL';
+}