diff --git a/solution/backend/crud/post_crud.py b/solution/backend/crud/post_crud.py
index 75f8052..e31f1ad 100644
--- a/solution/backend/crud/post_crud.py
+++ b/solution/backend/crud/post_crud.py
@@ -42,12 +42,12 @@ class PostCRUD:
         return result.scalar()
 
     async def due_for_mail(self, cdb: AsyncSession, status: int, today, limit: int):
-        """배정일이 오늘까지 온 것 중 업장당 1건만, 이른 날짜순."""
+        """배정일이 오늘인 것만, 업장당 1건."""
         result = await cdb.execute(
             select(place_posts)
             .where(
                 place_posts.status == status, place_posts.deleted == False,  # noqa: E712
-                place_posts.scheduled_date <= today,
+                place_posts.scheduled_date == today,
             )
             .distinct(place_posts.place_id)
             .order_by(place_posts.place_id, place_posts.scheduled_date)
@@ -62,9 +62,9 @@ class PostCRUD:
             .where(
                 place_posts.place_id == place_id, place_posts.status == status,
                 place_posts.deleted == False,  # noqa: E712
-                place_posts.scheduled_date <= today,
+                place_posts.scheduled_date == today,
             )
-            .order_by(place_posts.scheduled_date)
+            .order_by(place_posts.created_at)
             .limit(1)
         )
         return result.scalars().first()
diff --git a/solution/backend/tests/test_blog_owner.py b/solution/backend/tests/test_blog_owner.py
index 60fa008..6209cc6 100644
--- a/solution/backend/tests/test_blog_owner.py
+++ b/solution/backend/tests/test_blog_owner.py
@@ -1275,3 +1275,31 @@ async def test_send_now_mail_failure_alerts_once_and_recovers(client, db_engine,
     outcome["ok"] = True
     assert (await client.post(f"/v1/place/{place_id}/post/send-now", headers=h)).json()["result"]["success"] is True
     assert await kinds() == [("blog_send_failed", True), ("recovery", False)]
+
+
+async def test_mail_goes_only_for_todays_post_not_backlog(client, db_engine, auth_headers, monkeypatch):
+    from services import blog_jobs, mail_service
+
+    monkeypatch.setattr(mail_service, "is_configured", lambda: True)
+    sent_calls = []
+    monkeypatch.setattr(mail_service, "send", lambda **kwargs: sent_calls.append(kwargs) or True)
+
+    h = await auth_headers("bloggen-today")
+    place_id = await _place(client, h, name="오늘글펜션")
+    async with db_engine.begin() as conn:
+        await conn.execute(
+            text("INSERT INTO sites (site_id, place_id, domain, status) VALUES (:sid, :pid, :dom, :st)"),
+            {"sid": uuid.uuid4(), "pid": place_id, "dom": f"blog-test-{uuid.uuid4().hex[:8]}", "st": SiteStatus.PUBLISHED.value},
+        )
+        await conn.execute(text("UPDATE users SET email = :e WHERE id = :id"), {"e": "today@example.com", "id": "bloggen-today"})
+    old_post = await _seed_post(db_engine, place_id, scheduled=date.today() - timedelta(days=8))
+    today_post = await _seed_post(db_engine, place_id, scheduled=date.today())
+
+    res = await client.post(f"/v1/place/{place_id}/post/send-now", headers=h)
+    assert res.json()["result"]["success"] is True
+    assert await _status(db_engine, today_post) == PostStatus.SENT.value
+    assert await _status(db_engine, old_post) == PostStatus.REVIEWED.value
+
+    assert await blog_jobs.send_reviewed() == 0
+    assert await _status(db_engine, old_post) == PostStatus.REVIEWED.value
+    assert len(sent_calls) == 1