infrastructure-smtp

Generic MailSender over raw SMTP (RFC 5321/5322) — Postfix relay, SMTP AUTH, SES SMTP interface, selected by config, not per-provider code

What it is for

# infrastructure-smtp

Generic foundation_mail_message::MailSender implementation over raw SMTP (RFC 5321/5322), covering any backend reachable by host/port/TLS-mode/credentials: a local Postfix relay, an SMTP-AUTH account like mail.southcitycomputer.com's send side, or Amazon SES's SMTP interface. New code (Sprint 3.45 crate 4, see docs/userstories/sprint-3.45-mail-manager-harvest.md) — no rust-gmail-manager source, since that tool's sending/*.rs was Gmail-API-send-specific, not raw SMTP.

Uses lettre (already vendored in this workspace, at this exact version/feature set, by infrastructure-communication::smtp) rather than hand-rolling the SMTP protocol.

Implements MailSender only — never MailReader — per AC-capability-boundary: SMTP is structurally send-only, so this crate never fake-implements a read method it cannot perform. MailReader for mail.southcitycomputer.com's read side is infrastructure-imap (a separate crate), paired under one logical account at the tools-mail-manager config layer, not here.

Security (Gate 1.5.6)

• SMTP AUTH credentials (SmtpCredentials) are never logged:

SmtpConfig/SmtpCredentials's Debug impls redact password (see config.rs), and this crate never formats a config or credentials value into a log line.

• Message bodies are never logged above debug. The one debug! call

this crate makes (in SmtpSender::send) carries only a recipient count — never an address, subject, or body.

Capabilities

No public items.

How to use it

No examples/ target and no doctest in this crate's rustdoc. The tests listed under Verification are the closest executable usage.

Module structure

No public modules: the crate root is its whole surface.

Public surface

No public items.

Re-exports. Exported here, defined elsewhere.

Boundary

Reaches into foundation.

Shares tier infrastructure with 82 other crates: infrastructure-acquire, infrastructure-adapters-google-calendar, infrastructure-adapters-google-gmail, infrastructure-adapters-google-places, infrastructure-adapters-google-trends, infrastructure-adapters-shodan, infrastructure-adapters-yelp, infrastructure-agent, … (82 total).

_What this crate deliberately does NOT own is a judgment. No committed registry records one for it, so none is stated here._

Where it sits

Tier flow. Which tiers this crate's own edges cross.

flowchart LR
  n_infrastructure["infrastructure"] --> n_foundation["foundation"]

Dependencies

Runtime, in this workspace.

Runtime, from outside the workspace.

Development, from outside the workspace.

Build. None.

Depended on by. 1 workspace crate.

Signal flow — what reaches this crate, and what it reaches.

flowchart LR
  n_tools_mail_manager["tools-mail-manager"] -->|uses| SELF
  SELF["infrastructure-smtp"]
  SELF -->|runtime| n_foundation_mail_message["foundation-mail-message"]
  SELF -->|runtime| n_foundation_smtp_transport["foundation-smtp-transport"]
  classDef self fill:#1f883d,stroke:#1f883d,color:#fff;
  class SELF self;

Feature flags

No Cargo features are defined: every capability is unconditional, so no consumer can receive a half-wired crate.

Targets

Error model

No public error type was detected: no public item declares a type named *Error, and no public signature returns one.

Operational characteristics

No unsafe block, unsafe fn, unsafe impl or unsafe trait was found by the parser anywhere in this crate's source.

Configuration

No environment variable is read with a literal name anywhere in this crate. A variable whose key is computed at run time cannot be listed here, and is not claimed to be absent.

Related capabilities

1 workspace crate depends on this one: tools-mail-manager.

Verification

What the tests establish, by name:

• auth_failure_maps_to_authentication_error — tests/smtp_send.rs
• connection_refused_maps_to_transport_error — tests/smtp_send.rs
• rejected_recipient_maps_to_other_error — tests/smtp_send.rs
• send_with_no_recipients_is_rejected_before_any_network_call — tests/smtp_send.rs
• sends_successfully_to_a_no_auth_relay — tests/smtp_send.rs
• sends_with_credentials_and_they_reach_the_wire_correctly — tests/smtp_send.rs
• transient_failure_maps_to_transport_error — tests/smtp_send.rs
• config_debug_redacts_password_via_nested_credentials — src/config.rs
• config_defaults_to_no_credentials_and_starttls_for_a_bare_relay_config — src/config.rs
• config_round_trips_through_json — src/config.rs
• credentials_debug_redacts_password — src/config.rs
• tls_mode_serializes_snake_case_and_round_trips — src/config.rs
• build_from_mailbox_rejects_malformed_address — src/message.rs
• build_from_mailbox_with_display_name — src/message.rs
• build_from_mailbox_without_display_name — src/message.rs
• build_message_includes_to_cc_bcc_and_subject — src/message.rs
• build_message_rejects_attachment_with_no_content_loaded — src/message.rs
• build_message_rejects_invalid_to_address — src/message.rs
• build_message_rejects_no_recipients — src/message.rs
• build_message_single_text_part_is_plain_body — src/message.rs
• build_message_text_and_html_becomes_multipart_alternative — src/message.rs
• build_message_with_attachment_produces_multipart_mixed — src/message.rs
• build_message_with_no_body_parts_still_produces_a_valid_message — src/message.rs
• constructs_for_tls_mode_implicit_with_credentials_ses_shaped — src/sender.rs
• constructs_for_tls_mode_none_no_auth_local_relay — src/sender.rs
• constructs_for_tls_mode_start_tls_with_credentials — src/sender.rs
• rejects_malformed_from_address — src/sender.rs

Documentation coverage

Metrics

pie showData
    title Rust source composition
    "Code" : 495
    "Blank or comment" : 239

Generation

Rendered by tools-corpus corpus readme from repository evidence alone, renderer schema 2, lexicon current. No model, network service or database was consulted. Regenerate with tools-corpus corpus readme --write; verify with --check.