diff --git a/src/applications/calendar/controller/PhabricatorCalendarEventViewController.php b/src/applications/calendar/controller/PhabricatorCalendarEventViewController.php
--- a/src/applications/calendar/controller/PhabricatorCalendarEventViewController.php
+++ b/src/applications/calendar/controller/PhabricatorCalendarEventViewController.php
@@ -166,6 +166,7 @@
       }
 
       $availability_select->setDropdownMenu($dropdown);
+      $availability_select->setDisabled($event->isImportedEvent());
       $header->addActionLink($availability_select);
     }
 
@@ -629,6 +630,7 @@
       ->setIcon('fa-times grey')
       ->setHref($this->getApplicationURI("/event/decline/{$id}/"))
       ->setWorkflow(true)
+      ->setDisabled($event->isImportedEvent())
       ->setText(pht('Decline'));
 
     $accept_button = id(new PHUIButtonView())
@@ -636,6 +638,7 @@
       ->setIcon('fa-check green')
       ->setHref($this->getApplicationURI("/event/accept/{$id}/"))
       ->setWorkflow(true)
+      ->setDisabled($event->isImportedEvent())
       ->setText(pht('Accept'));
 
     return array($decline_button, $accept_button);
diff --git a/src/applications/calendar/import/PhabricatorCalendarImportEngine.php b/src/applications/calendar/import/PhabricatorCalendarImportEngine.php
--- a/src/applications/calendar/import/PhabricatorCalendarImportEngine.php
+++ b/src/applications/calendar/import/PhabricatorCalendarImportEngine.php
@@ -207,10 +207,17 @@
       $events = null;
     }
 
+    // Verified emails of the Calendar uploader.
+    $author_verified_emails = id(new PhabricatorUserEmail())->loadAllWhere(
+      'userPHID = %s AND isVerified = 1',
+      $import->getAuthorPHID());
+    $author_verified_emails = mpull($author_verified_emails, 'getAddress');
+
     $xactions = array();
     $update_map = array();
     $invitee_map = array();
-    $attendee_map = array();
+    $attendee_name_map = array(); // [eventUID][email from] = Attendee
+    $attendee_user_map = array(); // [eventUID][userPHID  ] = Attendee
     foreach ($node_map as $full_uid => $node) {
       $event = idx($events, $full_uid);
       if (!$event) {
@@ -227,17 +234,29 @@
       $xactions[$full_uid] = $this->newUpdateTransactions($event, $node);
       $update_map[$full_uid] = $event;
 
-      $attendee_map[$full_uid] = array();
+      $attendee_name_map[$full_uid] = array();
       $attendees = $node->getAttendees();
       $private_index = 1;
       foreach ($attendees as $attendee) {
+
         // Generate a "name" for this attendee which is not an email address.
         // We avoid disclosing email addresses to be consistent with the rest
         // of the product.
         $name = $attendee->getName();
         if (preg_match('/@/', $name)) {
-          $name = new PhutilEmailAddress($name);
-          $name = $name->getDisplayName();
+          $attendee_mail = new PhutilEmailAddress($name);
+          $name = $attendee_mail->getDisplayName();
+          $address = $attendee_mail->getAddress();
+
+          // Skip creation of dummy "Private User" if this Attendee is just
+          // a verified email owned by the Calendar uploader.
+          if ($address) {
+            if (in_array($address, $author_verified_emails, true)) {
+              $attendee_user_map[$full_uid][$import->getAuthorPHID()] =
+                $attendee;
+              continue;
+            }
+          }
         }
 
         // If we don't have a name or the name still looks like it's an
@@ -247,12 +266,12 @@
           $private_index++;
         }
 
-        $attendee_map[$full_uid][$name] = $attendee;
+        $attendee_name_map[$full_uid][$name] = $attendee;
       }
     }
 
     $attendee_names = array();
-    foreach ($attendee_map as $full_uid => $event_attendees) {
+    foreach ($attendee_name_map as $full_uid => $event_attendees) {
       foreach ($event_attendees as $name => $attendee) {
         $attendee_names[$name] = $attendee;
       }
@@ -356,13 +375,22 @@
       // We're just forcing attendees to the correct values here because
       // transactions intentionally don't let you RSVP for other users. This
       // might need to be turned into a special type of transaction eventually.
-      $attendees = $attendee_map[$full_uid];
+      $attendees_name = $attendee_name_map[$full_uid];
+      $attendees_user = idx($attendee_user_map, $full_uid, array());
       $old_map = $event->getInvitees();
       $old_map = mpull($old_map, null, 'getInviteePHID');
 
+      $phid_invitees = array();
+      foreach ($attendees_name as $name => $attendee) {
+        $attendee_phid = $external_invitees[$name]->getPHID();
+        $phid_invitees[$attendee_phid] = $attendee;
+      }
+      foreach ($attendees_user as $attendee_user_phid => $attendee) {
+        $phid_invitees[$attendee_user_phid] = $attendee;
+      }
+
       $new_map = array();
-      foreach ($attendees as $name => $attendee) {
-        $phid = $external_invitees[$name]->getPHID();
+      foreach ($phid_invitees as $phid => $attendee) {
 
         $invitee = idx($old_map, $phid);
         if (!$invitee) {
@@ -381,7 +409,11 @@
             break;
           case PhutilCalendarUserNode::STATUS_INVITED:
           default:
-            $status = PhabricatorCalendarEventInvitee::STATUS_INVITED;
+            if ($phid === $import->getAuthorPHID()) {
+              $status = PhabricatorCalendarEventInvitee::STATUS_ATTENDING;
+            } else {
+              $status = PhabricatorCalendarEventInvitee::STATUS_INVITED;
+            }
             break;
         }
         $invitee->setStatus($status);