diff --git a/app/schemas/eu.faircode.email.DB/4.json b/app/schemas/eu.faircode.email.DB/4.json
new file mode 100644
index 0000000000..a1df6281c5
--- /dev/null
+++ b/app/schemas/eu.faircode.email.DB/4.json
@@ -0,0 +1,659 @@
+{
+  "formatVersion": 1,
+  "database": {
+    "version": 4,
+    "identityHash": "ed5cc04cd8d171bff391cd8435cc29fe",
+    "entities": [
+      {
+        "tableName": "identity",
+        "createSql": "CREATE TABLE IF NOT EXISTS `${TABLE_NAME}` (`id` INTEGER PRIMARY KEY AUTOINCREMENT, `name` TEXT NOT NULL, `email` TEXT NOT NULL, `replyto` TEXT, `host` TEXT NOT NULL, `port` INTEGER NOT NULL, `starttls` INTEGER NOT NULL, `user` TEXT NOT NULL, `password` TEXT NOT NULL, `primary` INTEGER NOT NULL, `synchronize` INTEGER NOT NULL)",
+        "fields": [
+          {
+            "fieldPath": "id",
+            "columnName": "id",
+            "affinity": "INTEGER",
+            "notNull": false
+          },
+          {
+            "fieldPath": "name",
+            "columnName": "name",
+            "affinity": "TEXT",
+            "notNull": true
+          },
+          {
+            "fieldPath": "email",
+            "columnName": "email",
+            "affinity": "TEXT",
+            "notNull": true
+          },
+          {
+            "fieldPath": "replyto",
+            "columnName": "replyto",
+            "affinity": "TEXT",
+            "notNull": false
+          },
+          {
+            "fieldPath": "host",
+            "columnName": "host",
+            "affinity": "TEXT",
+            "notNull": true
+          },
+          {
+            "fieldPath": "port",
+            "columnName": "port",
+            "affinity": "INTEGER",
+            "notNull": true
+          },
+          {
+            "fieldPath": "starttls",
+            "columnName": "starttls",
+            "affinity": "INTEGER",
+            "notNull": true
+          },
+          {
+            "fieldPath": "user",
+            "columnName": "user",
+            "affinity": "TEXT",
+            "notNull": true
+          },
+          {
+            "fieldPath": "password",
+            "columnName": "password",
+            "affinity": "TEXT",
+            "notNull": true
+          },
+          {
+            "fieldPath": "primary",
+            "columnName": "primary",
+            "affinity": "INTEGER",
+            "notNull": true
+          },
+          {
+            "fieldPath": "synchronize",
+            "columnName": "synchronize",
+            "affinity": "INTEGER",
+            "notNull": true
+          }
+        ],
+        "primaryKey": {
+          "columnNames": [
+            "id"
+          ],
+          "autoGenerate": true
+        },
+        "indices": [],
+        "foreignKeys": []
+      },
+      {
+        "tableName": "account",
+        "createSql": "CREATE TABLE IF NOT EXISTS `${TABLE_NAME}` (`id` INTEGER PRIMARY KEY AUTOINCREMENT, `name` TEXT, `host` TEXT NOT NULL, `port` INTEGER NOT NULL, `user` TEXT NOT NULL, `password` TEXT NOT NULL, `primary` INTEGER NOT NULL, `synchronize` INTEGER NOT NULL)",
+        "fields": [
+          {
+            "fieldPath": "id",
+            "columnName": "id",
+            "affinity": "INTEGER",
+            "notNull": false
+          },
+          {
+            "fieldPath": "name",
+            "columnName": "name",
+            "affinity": "TEXT",
+            "notNull": false
+          },
+          {
+            "fieldPath": "host",
+            "columnName": "host",
+            "affinity": "TEXT",
+            "notNull": true
+          },
+          {
+            "fieldPath": "port",
+            "columnName": "port",
+            "affinity": "INTEGER",
+            "notNull": true
+          },
+          {
+            "fieldPath": "user",
+            "columnName": "user",
+            "affinity": "TEXT",
+            "notNull": true
+          },
+          {
+            "fieldPath": "password",
+            "columnName": "password",
+            "affinity": "TEXT",
+            "notNull": true
+          },
+          {
+            "fieldPath": "primary",
+            "columnName": "primary",
+            "affinity": "INTEGER",
+            "notNull": true
+          },
+          {
+            "fieldPath": "synchronize",
+            "columnName": "synchronize",
+            "affinity": "INTEGER",
+            "notNull": true
+          }
+        ],
+        "primaryKey": {
+          "columnNames": [
+            "id"
+          ],
+          "autoGenerate": true
+        },
+        "indices": [],
+        "foreignKeys": []
+      },
+      {
+        "tableName": "folder",
+        "createSql": "CREATE TABLE IF NOT EXISTS `${TABLE_NAME}` (`id` INTEGER PRIMARY KEY AUTOINCREMENT, `account` INTEGER, `name` TEXT NOT NULL, `type` TEXT NOT NULL, `synchronize` INTEGER NOT NULL, `after` INTEGER NOT NULL, FOREIGN KEY(`account`) REFERENCES `account`(`id`) ON UPDATE NO ACTION ON DELETE CASCADE )",
+        "fields": [
+          {
+            "fieldPath": "id",
+            "columnName": "id",
+            "affinity": "INTEGER",
+            "notNull": false
+          },
+          {
+            "fieldPath": "account",
+            "columnName": "account",
+            "affinity": "INTEGER",
+            "notNull": false
+          },
+          {
+            "fieldPath": "name",
+            "columnName": "name",
+            "affinity": "TEXT",
+            "notNull": true
+          },
+          {
+            "fieldPath": "type",
+            "columnName": "type",
+            "affinity": "TEXT",
+            "notNull": true
+          },
+          {
+            "fieldPath": "synchronize",
+            "columnName": "synchronize",
+            "affinity": "INTEGER",
+            "notNull": true
+          },
+          {
+            "fieldPath": "after",
+            "columnName": "after",
+            "affinity": "INTEGER",
+            "notNull": true
+          }
+        ],
+        "primaryKey": {
+          "columnNames": [
+            "id"
+          ],
+          "autoGenerate": true
+        },
+        "indices": [
+          {
+            "name": "index_folder_account_name",
+            "unique": true,
+            "columnNames": [
+              "account",
+              "name"
+            ],
+            "createSql": "CREATE UNIQUE INDEX `index_folder_account_name` ON `${TABLE_NAME}` (`account`, `name`)"
+          },
+          {
+            "name": "index_folder_account",
+            "unique": false,
+            "columnNames": [
+              "account"
+            ],
+            "createSql": "CREATE  INDEX `index_folder_account` ON `${TABLE_NAME}` (`account`)"
+          },
+          {
+            "name": "index_folder_name",
+            "unique": false,
+            "columnNames": [
+              "name"
+            ],
+            "createSql": "CREATE  INDEX `index_folder_name` ON `${TABLE_NAME}` (`name`)"
+          },
+          {
+            "name": "index_folder_type",
+            "unique": false,
+            "columnNames": [
+              "type"
+            ],
+            "createSql": "CREATE  INDEX `index_folder_type` ON `${TABLE_NAME}` (`type`)"
+          }
+        ],
+        "foreignKeys": [
+          {
+            "table": "account",
+            "onDelete": "CASCADE",
+            "onUpdate": "NO ACTION",
+            "columns": [
+              "account"
+            ],
+            "referencedColumns": [
+              "id"
+            ]
+          }
+        ]
+      },
+      {
+        "tableName": "message",
+        "createSql": "CREATE TABLE IF NOT EXISTS `${TABLE_NAME}` (`id` INTEGER PRIMARY KEY AUTOINCREMENT, `account` INTEGER, `folder` INTEGER NOT NULL, `identity` INTEGER, `replying` INTEGER, `uid` INTEGER, `msgid` TEXT, `references` TEXT, `inreplyto` TEXT, `thread` TEXT, `from` TEXT, `to` TEXT, `cc` TEXT, `bcc` TEXT, `reply` TEXT, `subject` TEXT, `body` TEXT, `sent` INTEGER, `received` INTEGER NOT NULL, `seen` INTEGER NOT NULL, `ui_seen` INTEGER NOT NULL, `ui_hide` INTEGER NOT NULL, FOREIGN KEY(`account`) REFERENCES `account`(`id`) ON UPDATE NO ACTION ON DELETE CASCADE , FOREIGN KEY(`folder`) REFERENCES `folder`(`id`) ON UPDATE NO ACTION ON DELETE CASCADE , FOREIGN KEY(`identity`) REFERENCES `identity`(`id`) ON UPDATE NO ACTION ON DELETE CASCADE , FOREIGN KEY(`replying`) REFERENCES `message`(`id`) ON UPDATE NO ACTION ON DELETE CASCADE )",
+        "fields": [
+          {
+            "fieldPath": "id",
+            "columnName": "id",
+            "affinity": "INTEGER",
+            "notNull": false
+          },
+          {
+            "fieldPath": "account",
+            "columnName": "account",
+            "affinity": "INTEGER",
+            "notNull": false
+          },
+          {
+            "fieldPath": "folder",
+            "columnName": "folder",
+            "affinity": "INTEGER",
+            "notNull": true
+          },
+          {
+            "fieldPath": "identity",
+            "columnName": "identity",
+            "affinity": "INTEGER",
+            "notNull": false
+          },
+          {
+            "fieldPath": "replying",
+            "columnName": "replying",
+            "affinity": "INTEGER",
+            "notNull": false
+          },
+          {
+            "fieldPath": "uid",
+            "columnName": "uid",
+            "affinity": "INTEGER",
+            "notNull": false
+          },
+          {
+            "fieldPath": "msgid",
+            "columnName": "msgid",
+            "affinity": "TEXT",
+            "notNull": false
+          },
+          {
+            "fieldPath": "references",
+            "columnName": "references",
+            "affinity": "TEXT",
+            "notNull": false
+          },
+          {
+            "fieldPath": "inreplyto",
+            "columnName": "inreplyto",
+            "affinity": "TEXT",
+            "notNull": false
+          },
+          {
+            "fieldPath": "thread",
+            "columnName": "thread",
+            "affinity": "TEXT",
+            "notNull": false
+          },
+          {
+            "fieldPath": "from",
+            "columnName": "from",
+            "affinity": "TEXT",
+            "notNull": false
+          },
+          {
+            "fieldPath": "to",
+            "columnName": "to",
+            "affinity": "TEXT",
+            "notNull": false
+          },
+          {
+            "fieldPath": "cc",
+            "columnName": "cc",
+            "affinity": "TEXT",
+            "notNull": false
+          },
+          {
+            "fieldPath": "bcc",
+            "columnName": "bcc",
+            "affinity": "TEXT",
+            "notNull": false
+          },
+          {
+            "fieldPath": "reply",
+            "columnName": "reply",
+            "affinity": "TEXT",
+            "notNull": false
+          },
+          {
+            "fieldPath": "subject",
+            "columnName": "subject",
+            "affinity": "TEXT",
+            "notNull": false
+          },
+          {
+            "fieldPath": "body",
+            "columnName": "body",
+            "affinity": "TEXT",
+            "notNull": false
+          },
+          {
+            "fieldPath": "sent",
+            "columnName": "sent",
+            "affinity": "INTEGER",
+            "notNull": false
+          },
+          {
+            "fieldPath": "received",
+            "columnName": "received",
+            "affinity": "INTEGER",
+            "notNull": true
+          },
+          {
+            "fieldPath": "seen",
+            "columnName": "seen",
+            "affinity": "INTEGER",
+            "notNull": true
+          },
+          {
+            "fieldPath": "ui_seen",
+            "columnName": "ui_seen",
+            "affinity": "INTEGER",
+            "notNull": true
+          },
+          {
+            "fieldPath": "ui_hide",
+            "columnName": "ui_hide",
+            "affinity": "INTEGER",
+            "notNull": true
+          }
+        ],
+        "primaryKey": {
+          "columnNames": [
+            "id"
+          ],
+          "autoGenerate": true
+        },
+        "indices": [
+          {
+            "name": "index_message_account",
+            "unique": false,
+            "columnNames": [
+              "account"
+            ],
+            "createSql": "CREATE  INDEX `index_message_account` ON `${TABLE_NAME}` (`account`)"
+          },
+          {
+            "name": "index_message_folder",
+            "unique": false,
+            "columnNames": [
+              "folder"
+            ],
+            "createSql": "CREATE  INDEX `index_message_folder` ON `${TABLE_NAME}` (`folder`)"
+          },
+          {
+            "name": "index_message_identity",
+            "unique": false,
+            "columnNames": [
+              "identity"
+            ],
+            "createSql": "CREATE  INDEX `index_message_identity` ON `${TABLE_NAME}` (`identity`)"
+          },
+          {
+            "name": "index_message_replying",
+            "unique": false,
+            "columnNames": [
+              "replying"
+            ],
+            "createSql": "CREATE  INDEX `index_message_replying` ON `${TABLE_NAME}` (`replying`)"
+          },
+          {
+            "name": "index_message_folder_uid",
+            "unique": true,
+            "columnNames": [
+              "folder",
+              "uid"
+            ],
+            "createSql": "CREATE UNIQUE INDEX `index_message_folder_uid` ON `${TABLE_NAME}` (`folder`, `uid`)"
+          },
+          {
+            "name": "index_message_thread",
+            "unique": false,
+            "columnNames": [
+              "thread"
+            ],
+            "createSql": "CREATE  INDEX `index_message_thread` ON `${TABLE_NAME}` (`thread`)"
+          },
+          {
+            "name": "index_message_received",
+            "unique": false,
+            "columnNames": [
+              "received"
+            ],
+            "createSql": "CREATE  INDEX `index_message_received` ON `${TABLE_NAME}` (`received`)"
+          },
+          {
+            "name": "index_message_ui_seen",
+            "unique": false,
+            "columnNames": [
+              "ui_seen"
+            ],
+            "createSql": "CREATE  INDEX `index_message_ui_seen` ON `${TABLE_NAME}` (`ui_seen`)"
+          }
+        ],
+        "foreignKeys": [
+          {
+            "table": "account",
+            "onDelete": "CASCADE",
+            "onUpdate": "NO ACTION",
+            "columns": [
+              "account"
+            ],
+            "referencedColumns": [
+              "id"
+            ]
+          },
+          {
+            "table": "folder",
+            "onDelete": "CASCADE",
+            "onUpdate": "NO ACTION",
+            "columns": [
+              "folder"
+            ],
+            "referencedColumns": [
+              "id"
+            ]
+          },
+          {
+            "table": "identity",
+            "onDelete": "CASCADE",
+            "onUpdate": "NO ACTION",
+            "columns": [
+              "identity"
+            ],
+            "referencedColumns": [
+              "id"
+            ]
+          },
+          {
+            "table": "message",
+            "onDelete": "CASCADE",
+            "onUpdate": "NO ACTION",
+            "columns": [
+              "replying"
+            ],
+            "referencedColumns": [
+              "id"
+            ]
+          }
+        ]
+      },
+      {
+        "tableName": "attachment",
+        "createSql": "CREATE TABLE IF NOT EXISTS `${TABLE_NAME}` (`id` INTEGER PRIMARY KEY AUTOINCREMENT, `message` INTEGER NOT NULL, `sequence` INTEGER NOT NULL, `name` TEXT, `type` TEXT NOT NULL, `size` INTEGER, `progress` INTEGER, `content` BLOB, FOREIGN KEY(`message`) REFERENCES `message`(`id`) ON UPDATE NO ACTION ON DELETE CASCADE )",
+        "fields": [
+          {
+            "fieldPath": "id",
+            "columnName": "id",
+            "affinity": "INTEGER",
+            "notNull": false
+          },
+          {
+            "fieldPath": "message",
+            "columnName": "message",
+            "affinity": "INTEGER",
+            "notNull": true
+          },
+          {
+            "fieldPath": "sequence",
+            "columnName": "sequence",
+            "affinity": "INTEGER",
+            "notNull": true
+          },
+          {
+            "fieldPath": "name",
+            "columnName": "name",
+            "affinity": "TEXT",
+            "notNull": false
+          },
+          {
+            "fieldPath": "type",
+            "columnName": "type",
+            "affinity": "TEXT",
+            "notNull": true
+          },
+          {
+            "fieldPath": "size",
+            "columnName": "size",
+            "affinity": "INTEGER",
+            "notNull": false
+          },
+          {
+            "fieldPath": "progress",
+            "columnName": "progress",
+            "affinity": "INTEGER",
+            "notNull": false
+          },
+          {
+            "fieldPath": "content",
+            "columnName": "content",
+            "affinity": "BLOB",
+            "notNull": false
+          }
+        ],
+        "primaryKey": {
+          "columnNames": [
+            "id"
+          ],
+          "autoGenerate": true
+        },
+        "indices": [
+          {
+            "name": "index_attachment_message",
+            "unique": false,
+            "columnNames": [
+              "message"
+            ],
+            "createSql": "CREATE  INDEX `index_attachment_message` ON `${TABLE_NAME}` (`message`)"
+          },
+          {
+            "name": "index_attachment_message_sequence",
+            "unique": true,
+            "columnNames": [
+              "message",
+              "sequence"
+            ],
+            "createSql": "CREATE UNIQUE INDEX `index_attachment_message_sequence` ON `${TABLE_NAME}` (`message`, `sequence`)"
+          }
+        ],
+        "foreignKeys": [
+          {
+            "table": "message",
+            "onDelete": "CASCADE",
+            "onUpdate": "NO ACTION",
+            "columns": [
+              "message"
+            ],
+            "referencedColumns": [
+              "id"
+            ]
+          }
+        ]
+      },
+      {
+        "tableName": "operation",
+        "createSql": "CREATE TABLE IF NOT EXISTS `${TABLE_NAME}` (`id` INTEGER PRIMARY KEY AUTOINCREMENT, `message` INTEGER NOT NULL, `name` TEXT NOT NULL, `args` TEXT, FOREIGN KEY(`message`) REFERENCES `message`(`id`) ON UPDATE NO ACTION ON DELETE CASCADE )",
+        "fields": [
+          {
+            "fieldPath": "id",
+            "columnName": "id",
+            "affinity": "INTEGER",
+            "notNull": false
+          },
+          {
+            "fieldPath": "message",
+            "columnName": "message",
+            "affinity": "INTEGER",
+            "notNull": true
+          },
+          {
+            "fieldPath": "name",
+            "columnName": "name",
+            "affinity": "TEXT",
+            "notNull": true
+          },
+          {
+            "fieldPath": "args",
+            "columnName": "args",
+            "affinity": "TEXT",
+            "notNull": false
+          }
+        ],
+        "primaryKey": {
+          "columnNames": [
+            "id"
+          ],
+          "autoGenerate": true
+        },
+        "indices": [
+          {
+            "name": "index_operation_message",
+            "unique": false,
+            "columnNames": [
+              "message"
+            ],
+            "createSql": "CREATE  INDEX `index_operation_message` ON `${TABLE_NAME}` (`message`)"
+          }
+        ],
+        "foreignKeys": [
+          {
+            "table": "message",
+            "onDelete": "CASCADE",
+            "onUpdate": "NO ACTION",
+            "columns": [
+              "message"
+            ],
+            "referencedColumns": [
+              "id"
+            ]
+          }
+        ]
+      }
+    ],
+    "setupQueries": [
+      "CREATE TABLE IF NOT EXISTS room_master_table (id INTEGER PRIMARY KEY,identity_hash TEXT)",
+      "INSERT OR REPLACE INTO room_master_table (id,identity_hash) VALUES(42, \"ed5cc04cd8d171bff391cd8435cc29fe\")"
+    ]
+  }
+}
\ No newline at end of file
diff --git a/app/src/main/java/eu/faircode/email/DB.java b/app/src/main/java/eu/faircode/email/DB.java
index 956c4a7769..bc3e79dfbd 100644
--- a/app/src/main/java/eu/faircode/email/DB.java
+++ b/app/src/main/java/eu/faircode/email/DB.java
@@ -40,7 +40,7 @@ import android.util.Log;
                 EntityAttachment.class,
                 EntityOperation.class
         },
-        version = 3,
+        version = 4,
         exportSchema = true
 )
 
@@ -76,6 +76,7 @@ public abstract class DB extends RoomDatabase {
         return builder
                 .addMigrations(MIGRATION_1_2)
                 .addMigrations(MIGRATION_2_3)
+                .addMigrations(MIGRATION_3_4)
                 .build();
     }
 
@@ -103,6 +104,14 @@ public abstract class DB extends RoomDatabase {
         }
     };
 
+    private static final Migration MIGRATION_3_4 = new Migration(3, 4) {
+        @Override
+        public void migrate(SupportSQLiteDatabase db) {
+            Log.i(Helper.TAG, "DB migration from version " + startVersion + " to " + endVersion);
+            db.execSQL("CREATE  INDEX `index_message_ui_seen` ON `message` (`ui_seen`)");
+        }
+    };
+
     public static class Converters {
         @TypeConverter
         public static byte[] fromString(String value) {
diff --git a/app/src/main/java/eu/faircode/email/EntityMessage.java b/app/src/main/java/eu/faircode/email/EntityMessage.java
index a3677f3f10..173877f92e 100644
--- a/app/src/main/java/eu/faircode/email/EntityMessage.java
+++ b/app/src/main/java/eu/faircode/email/EntityMessage.java
@@ -44,8 +44,8 @@ import static android.arch.persistence.room.ForeignKey.CASCADE;
                 @Index(value = {"replying"}),
                 @Index(value = {"folder", "uid"}, unique = true),
                 @Index(value = {"thread"}),
-                @Index(value = {"received"})
-                // ui_seen? ui_seen?
+                @Index(value = {"received"}),
+                @Index(value = {"ui_seen"}),
         }
 )
 public class EntityMessage {