How to parse email attachments with mail-parser?

Use the attachment() method on the parsed Message object to access attachments. It handles MIME parts and returns attachments with names and content, as shown in the example with nested messages and RFC2231 support.

Does mail-parser support UTF-7 encoding for emails?

Yes, mail-parser supports UTF-7 encoding along with 40 other character sets, including legacy ones, making it suitable for parsing emails with diverse and obsolete formats.

mail-parser vs lettre for email parsing in Rust – which is better?

mail-parser is optimized for high-performance, RFC-compliant parsing with zero-copy design, while lettre is a broader library that includes email building and sending. Choose mail-parser for parsing-heavy tasks and lettre for all-in-one email handling.

Is mail-parser production-ready and tested?

Yes, it's battle-tested with millions of real-world emails and used in production by Stalwart Mail Server. It's thoroughly fuzzed and tested with MIRI for memory safety and reliability.

How to extract text and HTML bodies from emails using mail-parser?

Use the body_text() and body_html() methods on the parsed message. The library automatically converts between formats when missing, per RFC 8621, as demonstrated in the example with HTML-to-text conversion.

What are the performance benchmarks for mail-parser?

The README cites high performance with perfect hashing and fast Base64 decoding. Benchmarks can be run with cargo bench --all-features, but it's designed for speed, using techniques like Chromium's decoder for efficiency.

Does mail-parser handle nested messages or MIME digests?

Yes, it fully supports nested messages and multipart/digest, allowing access to embedded emails and their contents, as shown in the example with attachment messages and complex MIME structures.

mail-parser — Fast Zero-Copy Email Parser

What is mail-parser?

mail-parser is a high-performance email parsing library for Rust that fully conforms to Internet Message Format (RFC 5322) and MIME standards. It is designed for reliability and speed, making it suitable for processing real-world email messages in production environments.

Target Audience

Rust developers building email processing applications, such as mail servers, spam filters, email clients, or data extraction tools that need to parse and analyze email messages.

Value Proposition

Developers choose mail-parser for its strict RFC compliance combined with a liberal parsing approach that handles non-conformant real-world emails, its zero-copy design for minimal memory allocation, and its high-performance implementation using perfect hashing and optimized Base64 decoding.

Fast and robust e-mail parsing library for Rust

Use Cases

Best For

Building email servers or mail transfer agents (MTAs) that need to parse incoming messages efficiently and reliably.
Developing spam filters or email security tools that require accurate extraction of headers, body content, and attachments from diverse email formats.
Creating email clients or archiving systems that must handle legacy encodings and complex MIME structures.
Implementing data processing pipelines that extract structured information from email corpora, including nested messages and multilingual content.
Writing email analysis tools for compliance, forensics, or logging that depend on RFC-compliant parsing with robust error handling.
Integrating email parsing functionality into Rust applications where memory safety and performance are critical, such as in high-throughput backend services.

Not Ideal For

Applications needing to construct or modify email messages, as it's parsing-only and requires the separate mail-builder crate.
Projects not written in Rust, since it's a Rust-specific crate with no bindings for other languages.
Teams looking for an all-in-one email solution with sending, SMTP, or IMAP support, as it focuses solely on parsing.
Simple scripting tasks where a lightweight, non-Rust parser suffices, due to Rust integration overhead.

Pros & Cons

Pros

RFC Compliance and Robustness

Fully conforms to RFC 5322 and MIME standards while liberally parsing non-conformant real-world emails, adhering to the Robustness Principle for reliable handling.

Zero-Copy Efficiency

Returns most strings as Cow<str> references to the input, minimizing memory allocations and improving performance for large-scale email processing, as highlighted in the zero-copy design.

Broad Encoding Support

Decodes messages in 41 character sets, including UTF-7 and legacy encodings via optional dependency, ensuring compatibility with emails dating back to 1995.

High Performance Parsing

Uses perfect hashing for header parsing and a fast Base64 decoder based on Chromium's implementation, optimized for speed in production environments.

Memory Safety and Testing

Written in 100% safe Rust with no external dependencies, thoroughly fuzzed and tested with MIRI, ensuring reliability and security.

Cons

No Email Building Support

The library only parses emails; constructing or modifying messages requires the separate mail-builder crate, adding complexity for full email handling workflows.

Optional Dependency for Encodings

Support for legacy multi-byte encodings like BIG5 or ISO-2022-JP depends on the optional encoding_rs crate, which can increase binary size and setup steps.

Limited to Parsing Functionality

It doesn't handle email sending, SMTP, IMAP, or other protocols, necessitating additional libraries for complete email applications, which might fragment the codebase.

Rust-Only Ecosystem

As a Rust crate, it's not usable in projects built with other programming languages, limiting its applicability to Rust-based systems and requiring Rust expertise.

Frequently Asked Questions

What is mail-parser?

Target Audience

Rust developers building email processing applications, such as mail servers, spam filters, email clients, or data extraction tools that need to parse and analyze email messages.

Value Proposition

Use Cases

Best For

Building email servers or mail transfer agents (MTAs) that need to parse incoming messages efficiently and reliably.
Developing spam filters or email security tools that require accurate extraction of headers, body content, and attachments from diverse email formats.
Creating email clients or archiving systems that must handle legacy encodings and complex MIME structures.
Implementing data processing pipelines that extract structured information from email corpora, including nested messages and multilingual content.
Writing email analysis tools for compliance, forensics, or logging that depend on RFC-compliant parsing with robust error handling.
Integrating email parsing functionality into Rust applications where memory safety and performance are critical, such as in high-throughput backend services.

Not Ideal For

Applications needing to construct or modify email messages, as it's parsing-only and requires the separate mail-builder crate.
Projects not written in Rust, since it's a Rust-specific crate with no bindings for other languages.
Teams looking for an all-in-one email solution with sending, SMTP, or IMAP support, as it focuses solely on parsing.
Simple scripting tasks where a lightweight, non-Rust parser suffices, due to Rust integration overhead.

Pros & Cons

Pros

RFC Compliance and Robustness

Fully conforms to RFC 5322 and MIME standards while liberally parsing non-conformant real-world emails, adhering to the Robustness Principle for reliable handling.

Zero-Copy Efficiency

Returns most strings as Cow<str> references to the input, minimizing memory allocations and improving performance for large-scale email processing, as highlighted in the zero-copy design.

Broad Encoding Support

Decodes messages in 41 character sets, including UTF-7 and legacy encodings via optional dependency, ensuring compatibility with emails dating back to 1995.

High Performance Parsing

Uses perfect hashing for header parsing and a fast Base64 decoder based on Chromium's implementation, optimized for speed in production environments.

Memory Safety and Testing

Written in 100% safe Rust with no external dependencies, thoroughly fuzzed and tested with MIRI, ensuring reliability and security.

Cons

No Email Building Support

The library only parses emails; constructing or modifying messages requires the separate mail-builder crate, adding complexity for full email handling workflows.

Optional Dependency for Encodings

Support for legacy multi-byte encodings like BIG5 or ISO-2022-JP depends on the optional encoding_rs crate, which can increase binary size and setup steps.

Limited to Parsing Functionality

It doesn't handle email sending, SMTP, IMAP, or other protocols, necessitating additional libraries for complete email applications, which might fragment the codebase.

Rust-Only Ecosystem

As a Rust crate, it's not usable in projects built with other programming languages, limiting its applicability to Rust-based systems and requiring Rust expertise.

Frequently Asked Questions

mail-parser

What is mail-parser?

Overview

Use Cases

Best For

Not Ideal For

Pros & Cons

Pros

Cons

Frequently Asked Questions

Related Projects

Found a gem we're missing?

mail-parser

What is mail-parser?

Overview

Use Cases

Best For

Not Ideal For

Pros & Cons

Pros

Cons

Frequently Asked Questions

Related Projects

Found a gem we're missing?