Headers

mail_intake.parsers.headers

Summary

Message header parsing utilities for Mail Intake.

This module provides helper functions for normalizing and extracting useful information from provider-native message headers.

The functions here are intentionally simple and tolerant of malformed or incomplete header data.

Functions

extract_sender

extract_sender(headers: Dict[str, str]) -> Tuple[str, Optional[str]]

Extract sender email and optional display name from headers.

Parameters:

Name	Type	Description	Default
headers	Dict[str, str]	Normalized header dictionary as returned by parse_headers().	required

Returns:

Type	Description
Tuple[str, Optional[str]]	Tuple[str, Optional[str]]: A tuple (email, name) where email is the sender email address and name is the display name, or None if unavailable.

Notes

Responsibilities:

- This function parses the `From` header and attempts to extract
  sender email address and optional human-readable display name.

Example

Typical values:

• "John Doe <john@example.com>" -> ("john@example.com", "John Doe")
• "john@example.com" -> ("john@example.com", None)

parse_headers

parse_headers(raw_headers: List[Dict[str, str]]) -> Dict[str, str]

Convert a list of Gmail-style headers into a normalized dict.

Parameters:

Name	Type	Description	Default
raw_headers	List[Dict[str, str]]	List of header dictionaries, each containing name and value keys.	required

Returns:

Type	Description
Dict[str, str]	Dict[str, str]: Dictionary mapping lowercase header names to stripped values.

Notes

Guarantees:

- Provider payloads (such as Gmail) typically represent headers as a
  list of name/value mappings.
- This function normalizes them into a case-insensitive dictionary
  keyed by lowercase header names.

Example

Typical usage:

Input:
    [
        {"name": "From", "value": "John Doe <john@example.com>"},
        {"name": "Subject", "value": "Re: Interview Update"},
    ]

Output:
    {
        "from": "John Doe <john@example.com>",
        "subject": "Re: Interview Update",
    }