intermittent commit

src/govoplan_mail/backend/sending/smtp.py

@@ -1,6 +1,7 @@
 from __future__ import annotations
 
 import copy
+import logging
 import smtplib
 import ssl
 from dataclasses import dataclass
@@ -15,6 +16,8 @@ from govoplan_mail.backend.dev.mock_mailbox import (
     record_smtp_delivery,
 )
 
+logger = logging.getLogger(__name__)
+
 
 class SmtpConfigurationError(ValueError):
     """Raised when SMTP settings are incomplete or inconsistent."""
@@ -56,6 +59,10 @@ class SmtpSendResult:
         return len(self.envelope_recipients) - len(self.refused_recipients)
 
 
+def _log_smtp_cleanup_failure(action: str, exc: BaseException) -> None:
+    logger.debug("SMTP cleanup failed while %s: %s", action, exc, exc_info=True)
+
+
 def _require_smtp_config(config: SmtpConfig) -> tuple[str, int]:
     if not config.host:
         raise SmtpConfigurationError("SMTP host is required")
@@ -89,8 +96,8 @@ def _open_smtp(config: SmtpConfig) -> smtplib.SMTP:
         # on GC, but explicit cleanup is safer when the variable exists.
         try:
             smtp.quit()  # type: ignore[possibly-undefined]
-        except Exception:
-            pass
+        except Exception as cleanup_exc:
+            _log_smtp_cleanup_failure("opening connection", cleanup_exc)
         raise
 
 
@@ -134,11 +141,12 @@ def test_smtp_login(*, smtp_config: SmtpConfig) -> SmtpLoginTestResult:
     finally:
         try:
             smtp.quit()
-        except Exception:
+        except Exception as quit_exc:
+            _log_smtp_cleanup_failure("testing login quit", quit_exc)
             try:
                 smtp.close()
-            except Exception:
-                pass
+            except Exception as close_exc:
+                _log_smtp_cleanup_failure("testing login close", close_exc)
 
 
 def prepare_test_message(
@@ -161,12 +169,12 @@ def prepare_test_message(
             del test_message[header]
 
     # Replace potential previous marker headers if the user test-sends an EML twice.
-    for header in ["X-MultiMailer-Test-Send"]:
+    for header in ["X-GovOPlaN-Test-Send"]:
         if header in test_message:
             del test_message[header]
 
     test_message["To"] = formataddr((test_recipient_name or test_recipient, test_recipient))
-    test_message["X-MultiMailer-Test-Send"] = "true"
+    test_message["X-GovOPlaN-Test-Send"] = "true"
     return test_message
 
 
@@ -177,43 +185,97 @@ def _send_smtp_payload(
     envelope_from: str,
     envelope_recipients: list[str],
 ) -> SmtpSendResult:
+    host, port, recipients = _prepare_smtp_send(
+        smtp_config=smtp_config,
+        envelope_from=envelope_from,
+        envelope_recipients=envelope_recipients,
+    )
+
+    if is_mock_smtp_host(smtp_config.host):
+        _accepted, refused = _send_mock_smtp_payload(
+            message,
+            smtp_config=smtp_config,
+            envelope_from=envelope_from,
+            envelope_recipients=recipients,
+        )
+        return _smtp_send_result(
+            smtp_config=smtp_config,
+            host=host,
+            port=port,
+            envelope_from=envelope_from,
+            envelope_recipients=recipients,
+            refused=refused,
+        )
+
+    refused = _send_network_smtp_payload(
+        message,
+        smtp_config=smtp_config,
+        envelope_from=envelope_from,
+        envelope_recipients=recipients,
+    )
+    return _smtp_send_result(
+        smtp_config=smtp_config,
+        host=host,
+        port=port,
+        envelope_from=envelope_from,
+        envelope_recipients=recipients,
+        refused=refused,
+    )
+
+
+def _prepare_smtp_send(
+    *,
+    smtp_config: SmtpConfig,
+    envelope_from: str,
+    envelope_recipients: list[str],
+) -> tuple[str, int, list[str]]:
     host, port = _require_smtp_config(smtp_config)
     if not envelope_from:
         raise SmtpConfigurationError("SMTP envelope sender is required")
-    if not envelope_recipients:
+    recipients = [recipient for recipient in envelope_recipients if recipient]
+    if not recipients:
         raise SmtpConfigurationError("at least one SMTP envelope recipient is required")
+    return host, port, recipients
 
-    if is_mock_smtp_host(smtp_config.host):
-        if consume_fail_next_smtp():
-            raise SmtpSendError("Mock SMTP configured to fail the next send")
-        failures = get_failures()
-        reject_text = str(failures.get("smtp_reject_recipients_containing") or "").strip().lower()
-        refused: dict[str, tuple[int, bytes]] = {}
-        accepted = list(envelope_recipients)
-        if reject_text:
-            refused = {
-                recipient: (550, b"mock recipient rejected")
-                for recipient in envelope_recipients
-                if reject_text in recipient.lower()
-            }
-            accepted = [recipient for recipient in envelope_recipients if recipient not in refused]
-            if not accepted:
-                raise SmtpSendError(f"all mock SMTP recipients were refused: {_decode_refused(refused)}")
-        record_smtp_delivery(
-            message,
-            envelope_from=envelope_from,
-            envelope_recipients=accepted,
-            smtp_host=smtp_config.host,
-        )
-        return SmtpSendResult(
-            host=host,
-            port=port,
-            security=smtp_config.security.value,
-            envelope_from=envelope_from,
-            envelope_recipients=list(envelope_recipients),
-            refused_recipients=_decode_refused(refused),
-        )
 
+def _send_mock_smtp_payload(
+    message: EmailMessage | bytes,
+    *,
+    smtp_config: SmtpConfig,
+    envelope_from: str,
+    envelope_recipients: list[str],
+) -> tuple[list[str], dict[str, tuple[int, bytes]]]:
+    if consume_fail_next_smtp():
+        raise SmtpSendError("Mock SMTP configured to fail the next send")
+    failures = get_failures()
+    reject_text = str(failures.get("smtp_reject_recipients_containing") or "").strip().lower()
+    refused: dict[str, tuple[int, bytes]] = {}
+    accepted = list(envelope_recipients)
+    if reject_text:
+        refused = {
+            recipient: (550, b"mock recipient rejected")
+            for recipient in envelope_recipients
+            if reject_text in recipient.lower()
+        }
+        accepted = [recipient for recipient in envelope_recipients if recipient not in refused]
+        if not accepted:
+            raise SmtpSendError(f"all mock SMTP recipients were refused: {_decode_refused(refused)}")
+    record_smtp_delivery(
+        message,
+        envelope_from=envelope_from,
+        envelope_recipients=accepted,
+        smtp_host=smtp_config.host,
+    )
+    return accepted, refused
+
+
+def _send_network_smtp_payload(
+    message: EmailMessage | bytes,
+    *,
+    smtp_config: SmtpConfig,
+    envelope_from: str,
+    envelope_recipients: list[str],
+) -> dict[str, tuple[int, bytes]]:
     try:
         smtp = _open_smtp(smtp_config)
     except smtplib.SMTPAuthenticationError as exc:
@@ -266,12 +328,24 @@ def _send_smtp_payload(
     finally:
         try:
             smtp.quit()
-        except Exception:
+        except Exception as quit_exc:
+            _log_smtp_cleanup_failure("sending message quit", quit_exc)
             try:
                 smtp.close()
-            except Exception:
-                pass
+            except Exception as close_exc:
+                _log_smtp_cleanup_failure("sending message close", close_exc)
+    return refused
 
+
+def _smtp_send_result(
+    *,
+    smtp_config: SmtpConfig,
+    host: str,
+    port: int,
+    envelope_from: str,
+    envelope_recipients: list[str],
+    refused: dict[str, tuple[int, bytes]],
+) -> SmtpSendResult:
     return SmtpSendResult(
         host=host,
         port=port,