fix: Date/Message-ID/From-name on ticket emails, richer body (1.6.1-aio.9)

A tester's ticket email landed in spam. A mail-tester run against demo
scored 8.3/10 with SPF, DKIM and DMARC all passing through the VPS relay,
so the deductions were all in the message: MISSING_DATE (1.4),
HTML_IMAGE_ONLY_04 (0.3), MISSING_MID (0.1) — and Gmail/Outlook weigh a
missing Date/Message-ID as "machine-generated" far more than that.

- `build_ticket_email` sets Date, a Message-ID under the sender domain,
  and a From display name from `lnbits_site_title`.
- The body now carries the event name, dates, location, name on ticket,
  ticket id and the door instruction, so the HTML part is no longer a
  QR with a handful of words.

Upstream candidate: lnbits core `send_email` has the same omissions.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01EYwoAkZZmXMMmaBp4WGUBo

config.json

@@ -1,6 +1,6 @@
 {
   "id": "events",
-  "version": "1.6.1-aio.8",
+  "version": "1.6.1-aio.9",
   "name": "Events",
   "repo": "https://git.atitlan.io/aiolabs/events",
   "short_description": "Sell and register event tickets",

docs/upstream-candidates.md

@@ -4,14 +4,15 @@ Running log of fork features that are shaped so they could be offered to
 `lnbits/events` (or `lnbits/lnbits`). Add a row whenever a change lands here
 in an upstream-compatible form; strike it when the PR merges upstream.
 
-| Feature                                                                                        | Where                                                        | Upstream target                                                                                            | Readiness                                |
+| Feature                                                                                                         | Where                                                        | Upstream target                                                                                             | Readiness                                                                        |
-| ---------------------------------------------------------------------------------------------- | ------------------------------------------------------------ | ---------------------------------------------------------------------------------------------------------- | ---------------------------------------- |
+| --------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------ | ----------------------------------------------------------------------------------------------------------- | -------------------------------------------------------------------------------- |
-| `frontend_url` + origin allow-list + `?checkout=` return contract                              | `views_api.py` `_resolve_frontend_root`, `api_ticket_create` | lnbits/events                                                                                              | after the #33 rebase, as a small PR      |
+| `frontend_url` + origin allow-list + `?checkout=` return contract                                               | `views_api.py` `_resolve_frontend_root`, `api_ticket_create` | lnbits/events                                                                                               | after the #33 rebase, as a small PR                                              |
-| Ticket ids minted before the invoice so `success_url` can carry them                           | `api_ticket_create`                                          | lnbits/events                                                                                              | ships with the above                     |
+| Ticket ids minted before the invoice so `success_url` can carry them                                            | `api_ticket_create`                                          | lnbits/events                                                                                               | ships with the above                                                             |
-| `extra.checkout` (success/cancel URL, `customer_email`, line item, metadata) on fiat purchases | `api_ticket_create`                                          | lnbits/events (needs lnbits `StripeCheckoutOptions.cancel_url`/`customer_email`, PR'd from aiolabs/lnbits) | with the lnbits patch                    |
+| `extra.checkout` (success/cancel URL, `customer_email`, line item, metadata) on fiat purchases                  | `api_ticket_create`                                          | lnbits/events (needs lnbits `StripeCheckoutOptions.cancel_url`/`customer_email`, PR'd from aiolabs/lnbits)  | with the lnbits patch                                                            |
-| `extra.payment_methods` per event + `tickets_payment_methods` NIP-52 tag                       | `models.py`, `nostr_publisher.py`                            | lnbits/events (v2 PR #64 introduces the same field)                                                        | offer as review input on #64             |
+| `extra.payment_methods` per event + `tickets_payment_methods` NIP-52 tag                                        | `models.py`, `nostr_publisher.py`                            | lnbits/events (v2 PR #64 introduces the same field)                                                         | offer as review input on #64                                                     |
-| `asyncio.to_thread` around the smtplib send                                                    | `services.py` `_send_ticket_email_notification`              | lnbits/events                                                                                              | trivial, standalone                      |
+| `asyncio.to_thread` around the smtplib send                                                                     | `services.py` `_send_ticket_email_notification`              | lnbits/events                                                                                               | trivial, standalone                                                              |
-| QR logo overlay in `make_qr_png` (instance `lnbits_qr_logo`)                                   | `views_api.py`                                               | lnbits/events                                                                                              | standalone                               |
+| QR logo overlay in `make_qr_png` (instance `lnbits_qr_logo`)                                                    | `views_api.py`                                               | lnbits/events                                                                                               | standalone                                                                       |
-| Multi-ticket purchase as N rows on one `payment_hash`                                          | `api_ticket_create`, `crud.py`                               | lnbits/events                                                                                              | overlaps v2 baskets; review input on #64 |
+| Multi-ticket purchase as N rows on one `payment_hash`                                                           | `api_ticket_create`, `crud.py`                               | lnbits/events                                                                                               | overlaps v2 baskets; review input on #64                                         |
-| Free tickets without minting an invoice                                                        | `_issue_free_tickets`                                        | lnbits/events                                                                                              | small, standalone                        |
+| Free tickets without minting an invoice                                                                         | `_issue_free_tickets`                                        | lnbits/events                                                                                               | small, standalone                                                                |
-| NIP-52 publishing + approval workflow                                                          | `nostr_*.py`, `views_api.py`                                 | lnbits/events #46                                                                                          | open; rebase onto v1.6.8                 |
+| NIP-52 publishing + approval workflow                                                                           | `nostr_*.py`, `views_api.py`                                 | lnbits/events #46                                                                                           | open; rebase onto v1.6.8                                                         |
+| `Date` + `Message-ID` + From display name on the ticket email (`build_ticket_email`); event details in the body | `services.py`                                                | lnbits/events (mailer) **and** lnbits/lnbits `send_email` (same omissions, hits password-reset/admin mails) | trivial, standalone — measured: SpamAssassin MISSING_DATE 1.4 + MISSING_MID 0.14 |

services.py

@@ -5,6 +5,7 @@ import smtplib
 from asyncio.tasks import create_task
 from email.mime.multipart import MIMEMultipart
 from email.mime.text import MIMEText
+from email.utils import formataddr, formatdate, make_msgid
 from html import escape
 
 from lnbits.core.models.users import UserNotifications
@@ -114,12 +115,34 @@ def _ticket_notification_message(ticket: Ticket, event: Event) -> tuple[str, str
     return subject, f"{body}\n\nOpen it here: {ticket_url}"
 
 
-def _ticket_delivery_message(ticket: Ticket, base_message: str) -> str:
+def _ticket_details(ticket: Ticket, event: Event) -> str:
-    return f"{base_message}\n\nTicket image: {_ticket_image_url(ticket)}"
+    """Human-readable ticket facts for the email body. Also what keeps the
+    mail from being an image with no words (SpamAssassin HTML_IMAGE_ONLY)."""
+    when = event.event_start_date
+    if event.event_end_date and event.event_end_date != event.event_start_date:
+        when = f"{when} to {event.event_end_date}"
+    lines = [f"Event: {event.name}", f"When: {when}"]
+    if event.location:
+        lines.append(f"Where: {event.location}")
+    if ticket.name:
+        lines.append(f"Name on ticket: {ticket.name}")
+    lines.append(f"Ticket ID: {ticket.id}")
+    lines.append(
+        "Show the QR code below (or open the link above on your phone) at the "
+        "door to be scanned in."
+    )
+    return "\n".join(lines)
 
 
-def _ticket_email_html_message(ticket: Ticket, base_message: str) -> str:
+def _ticket_delivery_message(ticket: Ticket, event: Event, base_message: str) -> str:
-    text_message = _ticket_delivery_message(ticket, base_message)
+    return (
+        f"{base_message}\n\n{_ticket_details(ticket, event)}"
+        f"\n\nTicket image: {_ticket_image_url(ticket)}"
+    )
+
+
+def _ticket_email_html_message(ticket: Ticket, event: Event, base_message: str) -> str:
+    text_message = _ticket_delivery_message(ticket, event, base_message)
     html_message = f"<p>{escape(text_message).replace(chr(10), '<br />')}</p>"
     image_url = escape(_ticket_image_url(ticket), quote=True)
     return (
@@ -131,8 +154,8 @@ def _ticket_email_html_message(ticket: Ticket, base_message: str) -> str:
 
 def _ticket_notification_payload(ticket: Ticket, event: Event) -> tuple[str, str, str]:
     subject, base_message = _ticket_notification_message(ticket, event)
-    text_message = _ticket_delivery_message(ticket, base_message)
+    text_message = _ticket_delivery_message(ticket, event, base_message)
-    html_message = _ticket_email_html_message(ticket, base_message)
+    html_message = _ticket_email_html_message(ticket, event, base_message)
     return subject, text_message, html_message
 
 
@@ -221,14 +244,7 @@ async def _send_ticket_email_notification(
         if not is_valid_email_address(address):
             raise ValueError(f"Invalid email address: {address}")
 
-    msg = MIMEMultipart("alternative")
+    msg = build_ticket_email(from_email, to_emails, subject, message, html_message)
-    msg["From"] = from_email
-    msg["To"] = ", ".join(to_emails)
-    msg["Subject"] = subject
-    msg.attach(MIMEText(message, "plain"))
-    if html_message:
-        msg.attach(MIMEText(html_message, "html"))
-
     username = settings.lnbits_email_notifications_username or from_email
     await asyncio.to_thread(
         _smtp_send,
@@ -242,6 +258,31 @@ async def _send_ticket_email_notification(
     )
 
 
+def build_ticket_email(
+    from_email: str,
+    to_emails: list[str],
+    subject: str,
+    message: str,
+    html_message: str | None = None,
+) -> MIMEMultipart:
+    """Assemble the multipart ticket email with the headers receivers score
+    on: a Date and a Message-ID (their absence is what SpamAssassin's
+    MISSING_DATE / MISSING_MID flag, and what Gmail/Outlook read as
+    machine-generated), and a display name on From so the sender is not a
+    bare address."""
+    msg = MIMEMultipart("alternative")
+    sender_name = (settings.lnbits_site_title or "").strip() or "Tickets"
+    msg["From"] = formataddr((sender_name, from_email))
+    msg["To"] = ", ".join(to_emails)
+    msg["Subject"] = subject
+    msg["Date"] = formatdate(localtime=True)
+    msg["Message-ID"] = make_msgid(domain=from_email.rsplit("@", 1)[-1])
+    msg.attach(MIMEText(message, "plain"))
+    if html_message:
+        msg.attach(MIMEText(html_message, "html"))
+    return msg
+
+
 def _smtp_send(
     server: str,
     port: int,

tests/test_ticket_email.py

@@ -0,0 +1,69 @@
+from datetime import datetime, timezone
+
+from lnbits.settings import settings
+
+from ..models import Event, Ticket
+from ..services import _ticket_notification_payload, build_ticket_email
+
+
+def _event(**overrides) -> Event:
+    data = {
+        "id": "evt1",
+        "wallet": "w",
+        "name": "Test Event",
+        "info": "",
+        "closing_date": "2030-01-01",
+        "event_start_date": "2030-01-01T16:00:00+01:00",
+        "event_end_date": "2030-01-01T20:00:00+01:00",
+        "location": "The Chateau",
+        "amount_tickets": 10,
+        "price_per_ticket": 5,
+        "time": datetime.now(timezone.utc),
+    }
+    data.update(overrides)
+    return Event(**data)
+
+
+def _ticket(**overrides) -> Ticket:
+    now = datetime.now(timezone.utc)
+    data = {
+        "id": "tkt1",
+        "wallet": "w",
+        "event": "evt1",
+        "name": "Ada",
+        "email": "ada@example.com",
+        "registered": False,
+        "paid": True,
+        "time": now,
+        "reg_timestamp": now,
+    }
+    data.update(overrides)
+    return Ticket(**data)
+
+
+def test_email_carries_date_message_id_and_display_name(monkeypatch):
+    monkeypatch.setattr(settings, "lnbits_site_title", "Oyez!")
+    msg = build_ticket_email(
+        "tickets@example.org", ["ada@example.com"], "Subj", "text", "<p>html</p>"
+    )
+    assert msg["Date"]
+    assert msg["Message-ID"].endswith("@example.org>")
+    assert msg["From"] == "Oyez! <tickets@example.org>"
+    parts = [p.get_content_type() for p in msg.get_payload()]
+    assert parts == ["text/plain", "text/html"]
+
+
+def test_payload_includes_event_details_and_qr(monkeypatch):
+    monkeypatch.setattr(settings, "lnbits_baseurl", "https://lnbits.example/")
+    subject, text, html = _ticket_notification_payload(_ticket(), _event())
+    assert "Test Event" in subject
+    for needle in (
+        "Event: Test Event",
+        "Where: The Chateau",
+        "Name on ticket: Ada",
+        "Ticket ID: tkt1",
+        "at the door",
+    ):
+        assert needle in text
+    assert "/events/api/v1/qr/tkt1" in text
+    assert "<img" in html and "Ticket ID: tkt1" in html