MPS-23: single warm sending identity for transactional mail

All transactional mail now sends From app.email.sender (default
no-reply@origin.makepostsell.com) instead of per-shop no-reply@<domain>,
with the shop name (or email.from_name) as the display name. The origin
identity is DKIM-signed (d=makepostsell.com) and SPF-authorized and
relays via mx1's warm IP, so operator custom-domain shops stop getting
spam-foldered. format_from_header() builds the From; send_email() gained
a from_name kwarg. Reply-To / per-shop contact email still TODO.

CLAUDE.md

@@ -40,6 +40,10 @@ Files are NEVER streamed through uwsgi. Our server only generates presigned URLs
 
 **NEVER** use `request.app["bucket.secure_uploads"]`, `request.app["bucket.secure_uploads.get_endpoint"]`, or `request.secure_uploads_client` directly in views or templates. These are only used internally by `request_methods.py` as fallbacks.
 
+### Transactional Email (lib/mail.py)
+
+All transactional mail (OTP login codes, receipts, sale/offer notifications, gift cards, invites) sends from **one warm sending identity**: `app.email.sender` (default `no-reply@origin.makepostsell.com`, overridable via `MPS_EMAIL_SENDER`) — *not* per-shop `no-reply@<shop-domain>`. The recipient-facing name is the **shop name** when in shop context, else `app.email.from_name` (default `Make Post Sell`); `lib/mail.py:format_from_header()` builds the `From:` header. Why a single identity: operator custom-domain shops (e.g. `shop.unturf.com`) have no DKIM key MPS controls and don't authorize MPS's sending IPs in SPF, so per-domain `From:` lands in spam. `origin.makepostsell.com` is DKIM-signed by opendkim on the origin box (`d=makepostsell.com`, selector `20190727`) and SPF-authorized (`v=spf1 a a:mx1.foxhop.net -all`), and outbound is relayed through `mx1.foxhop.net` (warm IP, see `foxhop-pillar/postfix/makepostsell.sls` → `postfix_relayhost`). Reply-To / per-shop contact email is still TODO — see `docs/tickets/mps-23.md`.
+
 ### Karaoke Pipeline (lib/karaoke.py)
 
 Disk-backed vocal isolation pipeline using spectral mid-side Wiener masking

development.ini

@@ -51,6 +51,15 @@ app.make_post_sell.root_domain_owner_email = ${MAKE_POST_SELL_DOMAIN_OWNER_EMAIL
 
 # app.email.relay = localhost:8025
 
+# Single warm sending identity for ALL transactional mail (OTP codes, receipts,
+# sale/offer notifications, gift cards, invites) — regardless of which shop or
+# custom domain it's for. origin.makepostsell.com is DKIM-signed (d=makepostsell.com)
+# and SPF-authorized (relayed via mx1.foxhop.net). See docs/tickets/mps-23.md.
+# The shop name (when in shop context) becomes the From display name; this is the
+# fallback display name for platform mail with no shop context.
+app.email.sender = ${MPS_EMAIL_SENDER:-no-reply@origin.makepostsell.com}
+app.email.from_name = ${MPS_EMAIL_FROM_NAME:-Make Post Sell}
+
 # TODO: these values should be moved to environment variables & we should create an
 # example app.env environment file.
 app.bucket.secure_uploads = ${MPS_APP_MAIN_BUCKET}

docs/tickets/mps-23.md

@@ -1,6 +1,20 @@
 # MPS-23 — Consolidated transactional sender identity + shop contact email
 
-**Status:** Open (DNS prep done; needs a decision on the Reply-To / shop-contact-email approach before code lands)
+**Status:** Core shipped (2026-05-12) — single sending identity + shop display
+name + DNS are live. **Remaining:** the Reply-To / shop-contact-email decision
+(see "Open question" below), and the optional `d=origin.makepostsell.com` DKIM
+key for author-domain-exact alignment.
+
+## Shipped
+- `app.email.sender` defaults to `no-reply@origin.makepostsell.com` (overridable
+  via `MPS_EMAIL_SENDER`); `app.email.from_name` defaults to `Make Post Sell`.
+- `lib/mail.py`: `format_from_header()` helper; `send_pyramid_email()` sets the
+  From display name to `request.shop.name` when in shop context, else
+  `email.from_name`. `send_email()` gained a `from_name` kwarg.
+- DNS: `origin.makepostsell.com TXT "v=spf1 a a:mx1.foxhop.net -all"` (in
+  `proxy.unturf.com/ingress/pdns-init.sh`). opendkim on the origin already signs
+  `*@*.makepostsell.com` with `d=makepostsell.com`, relayed via mx1's warm IP.
+- Tests: `TestMailFromHeader` in `test_models.py`.
 
 ## Problem
 

make_post_sell/lib/mail.py

@@ -28,6 +28,7 @@ import dkim
 import smtplib
 from email.mime.multipart import MIMEMultipart
 from email.mime.text import MIMEText
+from email.utils import formataddr
 
 # Catch socket errors when postfix isn't running...
 from socket import error as socket_error
@@ -36,6 +37,17 @@ import logging
 log = logging.getLogger(__name__)
 
 
+def format_from_header(from_name, sender_email):
+    """Build the From header value.
+
+    With a display name -> '"Acme Shop" <no-reply@origin.makepostsell.com>'.
+    Without -> the bare address. formataddr handles RFC-2047 encoding/quoting.
+    """
+    if from_name:
+        return formataddr((from_name, sender_email))
+    return sender_email
+
+
 def send_email(
     to_email,
     sender_email,
@@ -47,6 +59,7 @@ def send_email(
     dkim_selector="",
     dkim_signature_algorithm="ed25519-sha256",
     debug_mode=False,
+    from_name="",
 ):
     # The `email` library assumes it is working with string objects.
     # The `dkim` library assumes it is working with byte objects.
@@ -65,7 +78,7 @@ def send_email(
     msg.attach(MIMEText(message_text, "plain"))
     msg.attach(MIMEText(message_html, "html"))
     msg["To"] = to_email
-    msg["From"] = sender_email
+    msg["From"] = format_from_header(from_name, sender_email)
     msg["Subject"] = subject
 
     try:
@@ -151,6 +164,15 @@ def send_pyramid_email(request, to_email, subject, message_text, message_html):
         "email.dkim_signature_algorithm", "ed25519-sha256"
     )
 
+    # Recipient-facing sender name: the shop (when in shop context) so that one
+    # warm sending address (email.sender) can carry mail for every shop without
+    # the recipient seeing a generic no-reply@. Falls back to a configured
+    # platform name, then to nothing (bare address).
+    shop = getattr(request, "shop", None)
+    from_name = (getattr(shop, "name", "") if shop else "") or request.app.get(
+        "email.from_name", ""
+    )
+
     send_email(
         to_email,
         sender_email,
@@ -162,6 +184,7 @@ def send_pyramid_email(request, to_email, subject, message_text, message_html):
         dkim_selector,
         dkim_signature_algorithm,
         request.debug_mode,
+        from_name,
     )
 
 

make_post_sell/tests/test_models.py

@@ -4817,6 +4817,71 @@ class TestAuctionQuantity(unittest.TestCase):
             self.assertTrue(MpsAuction.is_lot_auction.fget(a))
 
 
+class TestMailFromHeader(unittest.TestCase):
+    """MPS-23: From header carries a display name (the shop, or a configured
+    platform fallback) in front of the single warm sending address."""
+
+    def test_format_from_header_bare(self):
+        from ..lib.mail import format_from_header
+
+        self.assertEqual(
+            format_from_header("", "no-reply@origin.makepostsell.com"),
+            "no-reply@origin.makepostsell.com",
+        )
+
+    def test_format_from_header_with_name(self):
+        from ..lib.mail import format_from_header
+
+        self.assertEqual(
+            format_from_header("Acme Shop", "no-reply@origin.makepostsell.com"),
+            "Acme Shop <no-reply@origin.makepostsell.com>",
+        )
+
+    def test_format_from_header_quotes_special(self):
+        from ..lib.mail import format_from_header
+
+        # formataddr quotes a display name containing a comma.
+        self.assertEqual(
+            format_from_header("Acme, Inc.", "no-reply@origin.makepostsell.com"),
+            '"Acme, Inc." <no-reply@origin.makepostsell.com>',
+        )
+
+    @mock.patch("make_post_sell.lib.mail.send_email")
+    def test_send_pyramid_email_uses_shop_name(self, mock_send_email):
+        from ..lib.mail import send_pyramid_email
+        from types import SimpleNamespace
+
+        request = mock.Mock()
+        request.domain = "shop.example"
+        request.debug_mode = True
+        request.shop = SimpleNamespace(name="Acme Shop")
+        request.app = {"email.sender": "no-reply@origin.makepostsell.com"}
+
+        send_pyramid_email(request, "buyer@example.com", "Hi", "text", "<p>html</p>")
+        # from_name is the final positional arg of send_email().
+        _, kwargs = mock_send_email.call_args
+        args = mock_send_email.call_args[0]
+        self.assertEqual(args[-1], "Acme Shop")
+        self.assertEqual(args[1], "no-reply@origin.makepostsell.com")
+
+    @mock.patch("make_post_sell.lib.mail.send_email")
+    def test_send_pyramid_email_falls_back_to_configured_name(self, mock_send_email):
+        from ..lib.mail import send_pyramid_email
+
+        request = mock.Mock()
+        request.domain = "my.makepostsell.com"
+        request.debug_mode = True
+        request.shop = None
+        request.app = {
+            "email.sender": "no-reply@origin.makepostsell.com",
+            "email.from_name": "Make Post Sell",
+        }
+
+        send_pyramid_email(request, "u@example.com", "Hi", "text", "<p>html</p>")
+        args = mock_send_email.call_args[0]
+        self.assertEqual(args[-1], "Make Post Sell")
+
+
 class TestEmailNotificationContent(unittest.TestCase):
     """MPS-20 + MPS-21: email helpers format templates with the right
     fields. Mocks the underlying send_pyramid_email to verify the call."""