diff --git a/bin/recategorize-messages.py b/bin/recategorize-messages.py
new file mode 100755
index 000000000..e4e4d0663
--- /dev/null
+++ b/bin/recategorize-messages.py
@@ -0,0 +1,175 @@
+#!/usr/bin/env python
+
+import datetime
+from collections.abc import Iterable
+from typing import Literal
+
+import click
+from sqlalchemy.orm import Query
+
+from inbox.mailsync.backends.imap.common import update_message_metadata
+from inbox.models.account import Account
+from inbox.models.backends.imap import ImapUid
+from inbox.models.folder import Folder
+from inbox.models.message import Message
+from inbox.models.namespace import Namespace
+from inbox.models.session import global_session_scope, session_scope
+
+AccountType = Literal["gmail", "generic", "outlook"]
+ALL_ACCOUNT_TYPES = frozenset({"gmail", "generic", "outlook"})
+
+
+def get_namespace_query(
+    entities: list,
+    *,
+    only_account_ids: Iterable[int] | None,
+    only_types: set[AccountType],
+) -> Query:
+    discriminators = {account_type + "account" for account_type in only_types}
+    namespace_query = (
+        Query(entities)
+        .join(Namespace.account)
+        .filter(Account.discriminator.in_(discriminators))
+    )
+    if only_account_ids is not None:
+        namespace_query = namespace_query.filter(
+            Namespace.account_id.in_(only_account_ids)
+        )
+
+    return namespace_query
+
+
+def get_total_namespace_count(
+    *,
+    only_account_ids: Iterable[int] | None,
+    only_types: set[AccountType] = ALL_ACCOUNT_TYPES,
+) -> int:
+    namespace_query = get_namespace_query(
+        [Namespace], only_account_ids=only_account_ids, only_types=only_types
+    )
+
+    with global_session_scope() as session:
+        return namespace_query.with_session(session).count()
+
+
+def yield_account_id_and_message_ids(
+    *,
+    only_account_ids: Iterable[int] | None,
+    date_start: datetime.date | None,
+    date_end: datetime.date | None,
+    only_inbox: bool,
+    only_types: set[AccountType] = ALL_ACCOUNT_TYPES,
+) -> Iterable[int, list[int]]:
+    namespace_query = get_namespace_query(
+        [Namespace.account_id, Namespace.id],
+        only_account_ids=only_account_ids,
+        only_types=only_types,
+    )
+
+    with global_session_scope() as session:
+        account_id_to_namespace_id = {
+            account_id: namespace_id
+            for account_id, namespace_id in namespace_query.with_session(session)
+        }
+
+    for account_id, namespace_id in account_id_to_namespace_id.items():
+        query = Query([Message.id]).filter(Message.namespace_id == namespace_id)
+
+        if only_inbox:
+            inbox_folder = ImapUid.folder.has(Folder._canonical_name == "INBOX")
+            query = query.filter(Message.imapuids.any(inbox_folder))
+        if date_start:
+            query = query.filter(Message.created_at >= date_start)
+        if date_end:
+            query = query.filter(Message.created_at <= date_end)
+
+        with global_session_scope() as session:
+            message_ids = [message_id for message_id, in query.with_session(session)]
+
+        yield account_id, message_ids
+
+
+def split_integers_separated_by_common(
+    ctx, param, comma_separated_value
+) -> list[int] | None:
+    if comma_separated_value is not None:
+        return [int(value) for value in comma_separated_value.split(",")]
+
+
+@click.command()
+@click.option("--date-start", type=click.DateTime(formats=["%Y-%m-%d"]), default=None)
+@click.option("--date-end", type=click.DateTime(formats=["%Y-%m-%d"]), default=None)
+@click.option(
+    "--only-account-ids",
+    type=str,
+    default=None,
+    callback=split_integers_separated_by_common,
+)
+@click.option("--only-inbox", is_flag=True, default=False)
+@click.option("--only-types", default=",".join(ALL_ACCOUNT_TYPES))
+@click.option("--only-categories", default=None)
+@click.option("--dry-run/--no-dry-run", default=True)
+def main(
+    only_account_ids: list[int] | None,
+    only_inbox: bool,
+    only_types: str,
+    only_categories: str | None,
+    date_start: datetime.date | None,
+    date_end: datetime.date | None,
+    dry_run: bool,
+) -> None:
+    print(
+        f"Settings: {only_account_ids=}, {only_inbox=}, {only_categories=}, {date_start=}, {date_end=}, {dry_run=}\n"
+    )
+
+    total_namespace_count = get_total_namespace_count(
+        only_account_ids=only_account_ids, only_types=set(only_types.split(","))
+    )
+    print(f"{total_namespace_count=}\n")
+
+    def session_factory():
+        return global_session_scope() if dry_run else session_scope(None)
+
+    for progress, (account_id, message_ids) in enumerate(
+        yield_account_id_and_message_ids(
+            only_account_ids=only_account_ids,
+            date_start=date_start,
+            date_end=date_end,
+            only_inbox=only_inbox,
+            only_types=only_types.split(","),
+        ),
+        start=1,
+    ):
+        print(f"{account_id=}, {len(message_ids)=}")
+
+        changed_counter = 0
+        for message_id in message_ids:
+            with session_factory() as session:
+                message = session.query(Message).get(message_id)
+                old_categories = set(
+                    category.name for category in message.categories if category.name
+                )
+                update_message_metadata(
+                    session, message.account, message, message.is_draft
+                )
+                new_categories = set(
+                    category.name for category in message.categories if category.name
+                )
+                if old_categories != new_categories:
+                    if only_categories and not new_categories & set(
+                        only_categories.split(",")
+                    ):
+                        session.rollback()
+                        continue
+
+                    changed_counter += 1
+                    print(
+                        f"\t{message.id=}, {message.message_id_header=}, {old_categories=} to {new_categories=}"
+                    )
+
+        print(f"{account_id=}, {changed_counter=}")
+        print(f"{progress=}, {total_namespace_count=}\n")
+
+
+if __name__ == "__main__":
+    main()