diff --git a/resources/sql/autopatches/20181220.pholio.01.mailkey.php b/resources/sql/autopatches/20181220.pholio.01.mailkey.php
new file mode 100644
--- /dev/null
+++ b/resources/sql/autopatches/20181220.pholio.01.mailkey.php
@@ -0,0 +1,28 @@
+<?php
+
+$mock_table = new PholioMock();
+$mock_conn = $mock_table->establishConnection('w');
+
+$properties_table = new PhabricatorMetaMTAMailProperties();
+$conn = $properties_table->establishConnection('w');
+
+$iterator = new LiskRawMigrationIterator(
+  $mock_conn,
+  $mock_table->getTableName());
+
+foreach ($iterator as $row) {
+  queryfx(
+    $conn,
+    'INSERT IGNORE INTO %T
+        (objectPHID, mailProperties, dateCreated, dateModified)
+      VALUES
+        (%s, %s, %d, %d)',
+    $properties_table->getTableName(),
+    $row['phid'],
+    phutil_json_encode(
+      array(
+        'mailKey' => $row['mailKey'],
+      )),
+    PhabricatorTime::getNow(),
+    PhabricatorTime::getNow());
+}
diff --git a/resources/sql/autopatches/20181220.pholio.02.dropmailkey.sql b/resources/sql/autopatches/20181220.pholio.02.dropmailkey.sql
new file mode 100644
--- /dev/null
+++ b/resources/sql/autopatches/20181220.pholio.02.dropmailkey.sql
@@ -0,0 +1,2 @@
+ALTER TABLE {$NAMESPACE}_pholio.pholio_mock
+  DROP mailKey;
diff --git a/src/applications/pholio/storage/PholioMock.php b/src/applications/pholio/storage/PholioMock.php
--- a/src/applications/pholio/storage/PholioMock.php
+++ b/src/applications/pholio/storage/PholioMock.php
@@ -25,7 +25,6 @@
   protected $name;
   protected $description;
   protected $coverPHID;
-  protected $mailKey;
   protected $status;
   protected $spacePHID;
 
@@ -65,15 +64,9 @@
       self::CONFIG_COLUMN_SCHEMA => array(
         'name' => 'text128',
         'description' => 'text',
-        'mailKey' => 'bytes20',
         'status' => 'text12',
       ),
       self::CONFIG_KEY_SCHEMA => array(
-        'key_phid' => null,
-        'phid' => array(
-          'columns' => array('phid'),
-          'unique' => true,
-        ),
         'authorPHID' => array(
           'columns' => array('authorPHID'),
         ),
@@ -81,15 +74,8 @@
     ) + parent::getConfiguration();
   }
 
-  public function generatePHID() {
-    return PhabricatorPHID::generateNewPHID('MOCK');
-  }
-
-  public function save() {
-    if (!$this->getMailKey()) {
-      $this->setMailKey(Filesystem::readRandomCharacters(20));
-    }
-    return parent::save();
+  public function getPHIDType() {
+    return PholioMockPHIDType::TYPECONST;
   }
 
   public function attachImages(array $images) {