add email sending functionality with Django Ninja API

api/schema.py

@@ -0,0 +1,24 @@
+from typing import List, Optional
+
+from ninja import Schema, Form, UploadedFile, File
+
+
+class UserSchema(Schema):
+    username: str
+    is_authenticated: bool
+
+
+class NewMailMessageIn(Schema):
+    from_email: str
+    subject: str
+    body: str # plain text fallback
+    to: str
+    html_body: str | None = None
+    cc: str | None = None
+    bcc: str | None = None
+    attachments: List[tuple] = []
+
+
+class NewBulkMailMessageIn(Schema):
+    from_email: str
+    messages: List[NewMailMessageIn]