foundation tier

`foundation-mail-message`

Provider-agnostic mail message types and MailReader/MailSender capability traits

Provider-agnostic mail message types and MailReader/MailSender capability traits

Tier	foundation
Role	unclassified (baselined)
Path	`crates/foundation/mail-message`
Edition	2021
Targets	foundation_mail_message
Public items	20 across 5 modules
Tests	25

What it is for

# foundation-mail-message

Provider-agnostic mail message types and capability traits.

See README.md for the full design rationale (OQ1-OQ3 resolutions).

Capabilities

`address (other)`

Shared From-style address parsing: email/display-name extraction, root-domain

Item
`fn extract_email_address(raw : & str) -> Option <String>`
`fn extract_display_name(raw : & str) -> Option <String>`
`fn extract_root_domain(domain : & str) -> String`
`fn is_noreply_local_part(local_part : & str) -> bool`
`fn is_machine_sender_local_part(local_part : & str) -> bool`

`MailError`

Mail operation errors.

Item
`pub enum MailError`

`MailReader`

MailReader — list/fetch capability trait.

Item
`pub trait MailReader`

`MailSender`

MailSender — send capability trait.

Item
`pub trait MailSender`

`SendReceipt`

MailSender — send capability trait.

Item
`pub struct SendReceipt`

`Attachment`

Provider-agnostic mail message types.

Item
`pub struct Attachment`

`Cursor`

Provider-agnostic mail message types.

Item
`pub struct Cursor`
`Cursor :: fn new(token : impl Into <String>) -> Self`
`Cursor :: fn as_str(& self) -> & str`

`Email`

Provider-agnostic mail message types.

Item
`pub struct Email`
`Email :: fn body_text(& self) -> Option <& str>`
`Email :: fn body_html(& self) -> Option <& str>`
`Email :: fn attachments(& self) -> Vec <& Attachment>`

`ListPage`

Provider-agnostic mail message types.

Item
`pub struct ListPage`

`MessageId`

Provider-agnostic mail message types.

Item
`pub struct MessageId`

`MessagePart`

Provider-agnostic mail message types.

Item
`pub enum MessagePart`

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

foundation_mail_message

address
error
reader
sender
types

flowchart TD
  n_foundation_mail_message["foundation_mail_message"]
  n_foundation_mail_message --> n_address["address"]
  n_foundation_mail_message --> n_error["error"]
  n_foundation_mail_message --> n_reader["reader"]
  n_foundation_mail_message --> n_sender["sender"]
  n_foundation_mail_message --> n_types["types"]

Public surface

`address`

Item	What it is
`fn extract_email_address(raw : & str) -> Option <String>`	Extract the email address embedded in a raw `From`-style header value (`"Name" <email@domain>`, bare `email@domain`, or a quoted-name variant)
`fn extract_display_name(raw : & str) -> Option <String>`	Extract the display name from `"Name" <email>` / `Name <email>`, if present.
`fn extract_root_domain(domain : & str) -> String`	The registrable root domain: the last two labels of `domain` (e.g
`fn is_noreply_local_part(local_part : & str) -> bool`	True for the closed set of conventional noreply local parts (`noreply`, `no-reply`, `no_reply`, `donotreply`, `do-not-reply`, `do_not_reply`) — exact match only, not a prefix check.
`fn is_machine_sender_local_part(local_part : & str) -> bool`	True for `is_noreply_local_part` plus a broader set of automated-sender local parts (`notifications`, `alerts`, `billing`, `mailer-daemon`, ...), matched as an exact local part or a `{pattern}-`/`{pattern}+` prefix (so `alerts-prod@` and `alerts+2@` both match `alerts`).

`error`

Item	What it is
`pub enum MailError`	Errors that can occur during `MailReader`/`MailSender` operations

`reader`

Item	What it is
`pub trait MailReader`	Capability trait for backends that can list and fetch mail

`sender`

Item	What it is
`pub struct SendReceipt`	The result of a successful `MailSender::send` call.
`pub trait MailSender`	Capability trait for backends that can send mail

`types`

Item	What it is
`pub enum MessagePart`	A single content piece of a message: one of its text/HTML bodies, or one attachment
`pub struct Attachment`	A file attached to (or embedded in) a message.
`pub struct Email`	A provider-agnostic mail message — the input to `MailSender::send` and the output of `MailReader::fetch`
`Email :: fn body_text(& self) -> Option <& str>`	The first `text/plain` part, if any.
`Email :: fn body_html(& self) -> Option <& str>`	The first `text/html` part, if any.
`Email :: fn attachments(& self) -> Vec <& Attachment>`	All attachment parts, in order.
`pub struct MessageId`	A bare message identifier returned by `MailReader::list` (OQ1)
`pub struct Cursor`	An opaque, backend-issued pagination cursor (OQ2)
`Cursor :: fn new(token : impl Into <String>) -> Self`	Wrap a backend-issued token
`Cursor :: fn as_str(& self) -> & str`	The raw token, to hand back to the same backend on the next call.
`pub struct ListPage`	One page of `MessageId`s from `MailReader::list`.

Re-exports. Exported here, defined elsewhere.

Export	Defined in
`MailError`	`error::MailError`
`MailReader`	`reader::MailReader`
`{Attachment,Cursor,Email,ListPage,MessageId,MessagePart}`	`types::{Attachment,Cursor,Email,ListPage,MessageId,MessagePart}`
`{MailSender,SendReceipt}`	`sender::{MailSender,SendReceipt}`
`{extract_display_name,extract_email_address,extract_root_domain,is_machine_sender_local_part,is_noreply_local_part,}`	`address::{extract_display_name,extract_email_address,extract_root_domain,is_machine_sender_local_part,is_noreply_local_part,}`

Boundary

Depends on no other workspace tier.

Shares tier foundation with 27 other crates: foundation-audit-log, foundation-basemodels, foundation-bounded-io, foundation-conversation-closure, foundation-crypto-sign, foundation-decisioning, foundation-encounter-vocabulary, foundation-fs-metadata, … (27 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 (ontology)	`foundation`
Architectural role (taxonomy)	`unclassified (baselined)`
Location	`crates/foundation/mail-message`
Vocabulary in force (lexicon)	`current`

Dependencies

Runtime, from outside the workspace.

Crate	Requirement	Features	Optional	Only on
`async-trait`	`^0.1`	—	no	always
`chrono`	`^0.4`	`serde`	no	always
`serde`	`^1`	`derive`	no	always
`serde_json`	`^1`	—	no	always
`thiserror`	`^2`	—	no	always

Development, from outside the workspace.

Crate	Requirement	Features	Optional	Only on
`tokio`	`^1`	`full`	no	always
`tokio-test`	`^0.4`	—	no	always

Build. None.

Depended on by. 9 workspace crates.

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

flowchart LR
  n_domain_sender_reputation["domain-sender-reputation"] -->|uses| SELF
  n_foundation_refresh_policy["foundation-refresh-policy"] -->|uses| SELF
  n_infrastructure_adapters_google_gmail["infrastructure-adapters-google-gmail"] -->|uses| SELF
  n_infrastructure_imap["infrastructure-imap"] -->|uses| SELF
  n_infrastructure_mail_extract["infrastructure-mail-extract"] -->|uses| SELF
  n_infrastructure_mail_headers["infrastructure-mail-headers"] -->|uses| SELF
  n_infrastructure_smtp["infrastructure-smtp"] -->|uses| SELF
  n_operations_mail_sync["operations-mail-sync"] -->|uses| SELF
  n_tools_mail_manager["tools-mail-manager"] -->|uses| SELF
  SELF["foundation-mail-message"]
  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

Kind	Name	Source
lib	`foundation_mail_message`	`src/lib.rs`

Error model

Error type	Named by
`MailError`	declared, no public signature returns it

Operational characteristics

Property	Evidence
async public surface	none detected
async runtime	none detected
database access	none detected
network I/O	none detected
unsafe code	none detected
environment variables	none detected

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.

9 workspace crates depend on this one: domain-sender-reputation, foundation-refresh-policy, infrastructure-adapters-google-gmail, infrastructure-imap, infrastructure-mail-extract, infrastructure-mail-headers, infrastructure-smtp, operations-mail-sync, tools-mail-manager.

Verification

Kind	Count
Unit tests	25
Integration tests	0
Examples	0
Doctests	0

Evidence by module. How often each public module is named by something executable.

Module	Tests	Examples	Consumers
`address`	5	0	10
`error`	1	0	5
`reader`	1	0	6
`sender`	2	0	10
`types`	6	0	27

What the tests establish, by name:

display_name_absent_for_bare_address — src/address.rs
display_name_present — src/address.rs
extracts_bare_address — src/address.rs
extracts_from_angle_brackets — src/address.rs
extracts_quoted_sender — src/address.rs
machine_sender_check_matches_the_pre_hoist_format_based_reference — src/address.rs
machine_sender_matches_hyphen_and_plus_suffixes — src/address.rs
noreply_local_part_is_exact_match_only — src/address.rs
root_domain_strips_subdomains — src/address.rs
reader_fetch_missing_id_returns_not_found — src/reader.rs
reader_list_folders_returns_provider_native_names — src/reader.rs
reader_list_respects_max_results — src/reader.rs
reader_only_backend_lists_and_fetches — src/reader.rs
dual_capability_backend_implements_both_traits_independently — src/sender.rs
sender_only_backend_sends_through_trait_object — src/sender.rs
sender_rejects_message_with_no_recipients — src/sender.rs
attachment_holds_metadata_and_optional_content — src/types.rs
cursor_does_not_parse_or_interpret_its_contents — src/types.rs
cursor_is_opaque_and_round_trips_through_serde — src/types.rs
email_attachments_are_extracted_from_parts — src/types.rs
email_body_text_and_html_read_from_parts — src/types.rs
email_with_no_body_parts_returns_none — src/types.rs
folders_field_holds_arbitrary_provider_native_names_gmail_and_imap_alike — src/types.rs
list_page_carries_messages_and_optional_next_cursor — src/types.rs
message_id_is_just_id_and_optional_thread_id — src/types.rs

Documentation coverage

Measure	Documented	Total
Public items with rustdoc	20	20
Public modules with a `//!` block	5	5

pie showData
    title Public items with rustdoc
    "Documented" : 20
    "No rustdoc detected" : 0

Metrics

Metric	Value
Rust source files	6
Source lines	1069
Code lines	718
Public API items	20
Public modules	5
Tests	25
Examples	0
Cargo features	0
Direct runtime dependencies	5
Workspace reverse dependencies	9

pie showData
    title Public API by kind
    "enum" : 2
    "function" : 5
    "method" : 5
    "struct" : 6
    "trait" : 2

pie showData
    title Rust source composition
    "Code" : 718
    "Blank or comment" : 351

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.

All foundation · Manual