diff --git a/infrastructure/email/ses_smtp_email_sender.py b/infrastructure/email/ses_smtp_email_sender.py
index 9318f100d..ba53d23bc 100644
--- a/infrastructure/email/ses_smtp_email_sender.py
+++ b/infrastructure/email/ses_smtp_email_sender.py
@@ -11,7 +11,7 @@ from __future__ import annotations
 import smtplib
 from email.message import EmailMessage
 from types import TracebackType
-from typing import Any, Callable, Optional, Protocol, Type
+from typing import Any, Callable, Optional, Protocol, Type, cast
 
 
 class SmtpTransport(Protocol):
@@ -35,7 +35,10 @@ class SmtpTransport(Protocol):
 
 
 def _default_smtp(host: str, port: int) -> SmtpTransport:
-    return smtplib.SMTP(host, port)
+    # `smtplib.SMTP` satisfies SmtpTransport structurally; its stdlib stubs
+    # declare wider signatures (extra optional args, an SMTP-typed context
+    # manager), so the cast bridges the real transport to the port's surface.
+    return cast(SmtpTransport, smtplib.SMTP(host, port))
 
 
 class SesSmtpEmailSender:
@@ -57,4 +60,12 @@ class SesSmtpEmailSender:
         self._smtp_factory = smtp_factory
 
     def send(self, *, to: str, subject: str, body: str) -> None:
-        raise NotImplementedError
+        message = EmailMessage()
+        message["From"] = self._from_address
+        message["To"] = to
+        message["Subject"] = subject
+        message.set_content(body)
+        with self._smtp_factory(self._host, self._port) as smtp:
+            smtp.starttls()
+            smtp.login(self._username, self._password)
+            smtp.send_message(message)