Add mailer.py

mailer.py

@@ -0,0 +1,34 @@
+"""Optional SMTP delivery of tenant reports."""
+import asyncio
+import smtplib
+from email.mime.multipart import MIMEMultipart
+from email.mime.text import MIMEText
+
+from config import Settings
+
+
+class MailNotConfigured(RuntimeError):
+    pass
+
+
+def _send_sync(s: Settings, to: str, subject: str, html: str):
+    msg = MIMEMultipart("alternative")
+    msg["Subject"] = subject
+    msg["From"] = s.smtp_from
+    msg["To"] = to
+    msg.attach(MIMEText(html, "html"))
+
+    with smtplib.SMTP(s.smtp_host, s.smtp_port, timeout=30) as server:
+        if s.smtp_tls:
+            server.starttls()
+        if s.smtp_user:
+            server.login(s.smtp_user, s.smtp_password)
+        server.send_message(msg)
+
+
+async def send_report(s: Settings, to: str, subject: str, html: str):
+    if not s.smtp_host:
+        raise MailNotConfigured(
+            "SMTP not configured — set BILLING_SMTP_HOST etc. in .env"
+        )
+    await asyncio.to_thread(_send_sync, s, to, subject, html)