Unhelpful logs for auth failures caused by SMTP server timeouts

[fnimick]

I experienced SMTP server timeouts (not errors) and the result was 504 errors from the api, and no indication that SMTP is the cause in the logs.

When the SMTP server errors, we get 500 errors with appropriate error messages, as expected.

A sample auth log event for the SMTP timeout:

[
  {
    "host": "db-pwgydselyeejhebljvsb",
    "component": "api",
    "_SYSTEMD_CGROUP": null,
    "request_id": "8f49f8f1a0914d17-BOS",
    "mail_from": null,
    "message": null,
    "_SOURCE_REALTIME_TIMESTAMP": null,
    "PRIORITY": null,
    "_AUDIT_LOGINUID": null,
    "panic": null,
    "metering": null,
    "UNIT": null,
    "event": null,
    "SYSLOG_FACILITY": null,
    "msg": "504: Processing this request timed out, please retry after a moment.",
    "mail_type": null,
    "EXECUTABLE": null,
    "user_id": null,
    "_CMDLINE": null,
    "action": null,
    "auth_event": [
      {
        "action": "user_confirmation_requested",
        "actor_id": "cdac3d23-a57e-4c22-a430-7526a39fa4f6",
        "actor_name": null,
        "actor_username": "redacted",
        "actor_via_sso": false,
        "log_type": "user",
        "traits": [
          {
            "channel": null,
            "identity_id": null,
            "provider": "email",
            "provider_id": null,
            "provider_type": null,
            "user_email": null,
            "user_id": null,
            "user_phone": null
          }
        ]
      }
    ],
    "level": "error",
    "_PID": null,
    "path": "/otp",
    "duration": null,
    "_COMM": null,
    "header": null,
    "_MACHINE_ID": null,
    "login_method": null,
    "_STREAM_ID": null,
    "source_type": null,
    "_LINE_BREAK": null,
    "_EXE": null,
    "_AUDIT_SESSION": null,
    "_TRANSPORT": null,
    "x_forwarded_proto": null,
    "time": null,
    "mail_to": null,
    "_GID": null,
    "stack": null,
    "x_forwarded_host": null,
    "status": null,
    "_UID": null,
    "method": "POST",
    "CODE_FILE": null,
    "remote_addr": "redacted",
    "provider": null,
    "_SYSTEMD_UNIT": null,
    "issuer": null,
    "error": "context deadline exceeded",
    "client_id": null,
    "MESSAGE_ID": null,
    "referer": "redacted",
    "_SYSTEMD_INVOCATION_ID": null,
    "CODE_FUNC": null,
    "_BOOT_ID": null,
    "INVOCATION_ID": null,
    "__MONOTONIC_TIMESTAMP": null,
    "timestamp": null,
    "__REALTIME_TIMESTAMP": null,
    "CODE_LINE": null,
    "_SYSTEMD_SLICE": null,
    "instance_id": null,
    "args": [],
    "SYSLOG_IDENTIFIER": null,
    "metadata": [],
    "_CAP_EFFECTIVE": null,
    "factor_id": null,
    "_SELINUX_CONTEXT": null,
    "project": null
  }
]