ebbe.bassandClaude Sonnet 5.5
20510a73e5
SMTP adapter with TLS and a fake, outbox with retries, backoff, rate limit and restart safety, scheduler tick with job-run records started by gunicorn, and a send_test_mail command. Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01N3t4WL7bd9bdHHNjEsxzqC
90 lines
3.4 KiB
Python
90 lines
3.4 KiB
Python
"""Sends e-mail through an SMTP server over TLS. The only module that talks SMTP (AD-1)."""
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from __future__ import annotations
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import logging
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import smtplib
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import ssl
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from email.message import EmailMessage
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from email.utils import formatdate, make_msgid
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from portal.config.env import SmtpConfig
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from .base import MailMessage, MailRejected, MailUnavailable
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logger = logging.getLogger(__name__)
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TIMEOUT_SECONDS = 20
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class SmtpMailer:
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def __init__(self, config: SmtpConfig, smtp_module=smtplib) -> None:
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self._config = config
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self._smtp = smtp_module
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def _build(self, message: MailMessage) -> EmailMessage:
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email = EmailMessage()
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# Setting a header that holds a line break raises ValueError, so no header injection.
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email["From"] = message.sender
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email["To"] = message.recipient
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email["Subject"] = message.subject
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email["Date"] = formatdate(localtime=False)
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email["Message-ID"] = make_msgid(domain=self._config.host)
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email.set_content(message.body_text, charset="utf-8")
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return email
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def _connect(self):
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config = self._config
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context = ssl.create_default_context() # verifies the certificate and the host name
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if config.security == "ssl":
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connection = self._smtp.SMTP_SSL(
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config.host, config.port, timeout=TIMEOUT_SECONDS, context=context
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)
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else:
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connection = self._smtp.SMTP(config.host, config.port, timeout=TIMEOUT_SECONDS)
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try:
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connection.ehlo()
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if config.security == "starttls":
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connection.starttls(context=context)
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connection.ehlo()
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connection.login(config.username, config.password)
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except BaseException:
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connection.close()
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raise
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return connection
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def send(self, message: MailMessage) -> None:
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try:
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email = self._build(message)
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except ValueError as exc:
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raise MailRejected("The message could not be built") from exc
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try:
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connection = self._connect()
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try:
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connection.send_message(email)
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finally:
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try:
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connection.quit()
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except (self._smtp.SMTPException, OSError):
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connection.close()
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except self._smtp.SMTPAuthenticationError as exc:
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# A configuration problem: the Admin fixes it and the retry works.
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logger.error("SMTP login refused (code %s)", exc.smtp_code)
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raise MailUnavailable(f"The mail server refused the login ({exc.smtp_code})") from exc
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except self._smtp.SMTPRecipientsRefused as exc:
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codes = [code for code, _ in exc.recipients.values()]
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raise _by_code(max(codes, default=0)) from exc
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except self._smtp.SMTPResponseException as exc:
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raise _by_code(exc.smtp_code) from exc
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except (self._smtp.SMTPException, OSError, ssl.SSLError) as exc:
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logger.warning("SMTP request failed: %s", type(exc).__name__)
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name = type(exc).__name__
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raise MailUnavailable(f"The mail server is not available ({name})") from exc
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def _by_code(code: int):
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"""Codes 5xx are permanent; everything else may work later."""
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if 500 <= code < 600:
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return MailRejected(f"The mail server refused the message ({code})")
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return MailUnavailable(f"The mail server could not take the message ({code})")
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