Add RFC email headers to report messages

src/pve_backup_report/email_report.py

@@ -2,6 +2,7 @@ from __future__ import annotations
 
 import smtplib
 from email.message import EmailMessage
+from email.utils import formatdate, make_msgid, parseaddr
 from pathlib import Path
 
 from pve_backup_report.config import EmailConfig
@@ -47,6 +48,9 @@ def build_report_message(config: EmailConfig, pdf_path: Path) -> EmailMessage:
     message["Subject"] = config.subject
     message["From"] = config.smtp_from or ""
     message["To"] = ", ".join(config.smtp_to)
+    message["Date"] = formatdate(localtime=True)
+    message["Message-ID"] = make_msgid(domain=message_id_domain(config.smtp_from))
+    message["Auto-Submitted"] = "auto-generated"
     message.set_content(
         "Bonjour,\n\n"
         "Veuillez trouver ci-joint le rapport de sauvegardes Proxmox VE.\n\n"
@@ -61,6 +65,16 @@ def build_report_message(config: EmailConfig, pdf_path: Path) -> EmailMessage:
     return message
 
 
+def message_id_domain(address: str | None) -> str | None:
+    if address is None:
+        return None
+    parsed_address = parseaddr(address)[1]
+    if "@" not in parsed_address:
+        return None
+    domain = parsed_address.rsplit("@", 1)[1].strip()
+    return domain or None
+
+
 def authenticate_and_send(
     smtp: smtplib.SMTP | smtplib.SMTP_SSL,
     config: EmailConfig,

tests/test_email_report.py

@@ -1,7 +1,11 @@
 from pathlib import Path
 
 from pve_backup_report.config import EmailConfig
-from pve_backup_report.email_report import build_report_message, send_report_email
+from pve_backup_report.email_report import (
+    build_report_message,
+    message_id_domain,
+    send_report_email,
+)
 
 
 def test_build_report_message_attaches_pdf(tmp_path: Path) -> None:
@@ -20,6 +24,9 @@ def test_build_report_message_attaches_pdf(tmp_path: Path) -> None:
     assert message["Subject"] == "Rapport PVE"
     assert message["From"] == "report@example.invalid"
     assert message["To"] == "admin@example.invalid"
+    assert message["Date"]
+    assert message["Message-ID"].endswith("@example.invalid>")
+    assert message["Auto-Submitted"] == "auto-generated"
     attachments = list(message.iter_attachments())
     assert len(attachments) == 1
     assert attachments[0].get_filename() == "rapport.pdf"
@@ -27,6 +34,13 @@ def test_build_report_message_attaches_pdf(tmp_path: Path) -> None:
     assert attachments[0].get_payload(decode=True) == b"%PDF-1.7"
 
 
+def test_message_id_domain_uses_sender_domain() -> None:
+    assert message_id_domain("PVE Report <pve@example.invalid>") == "example.invalid"
+    assert message_id_domain("pve@example.invalid") == "example.invalid"
+    assert message_id_domain("invalid") is None
+    assert message_id_domain(None) is None
+
+
 def test_send_report_email_uses_starttls_and_auth(tmp_path: Path, monkeypatch) -> None:
     pdf_path = tmp_path / "rapport.pdf"
     pdf_path.write_bytes(b"%PDF-1.7")