email-normalize

What it is and what it does

email-normalize is a Python 3.11+ library that takes email addresses and returns their canonical form by detecting the mailbox provider and applying provider-specific normalization rules. It handles behaviors like Gmail's plus addressing (foo+bar@gmail.com → foo@gmail.com) and period stripping (f.o.o@gmail.com → foo@gmail.com), and folds provider alias domains to a single form (googlemail.com → gmail.com). The library supports both synchronous and asynchronous workflows, with the async interface maintaining an LFRU cache of MX lookups for efficient batch processing.

The package normalizes against a known set of providers including Apple, Fastmail, Google, Microsoft, ProtonMail, Rackspace, Yandex, and Zoho. It can perform DNS lookups to detect custom domains and retrieve MX records, or skip DNS entirely and normalize only against well-known domains using a static map. This flexibility makes it suitable for scenarios ranging from simple email deduplication to comprehensive provider detection in applications that need to understand mailbox behavior.

Use it for:

• Deduplicating user email addresses in signup forms or databases where users may have entered equivalent addresses using plus addressing or periods.
• Detecting which mailbox provider a user is using to apply provider-specific features or restrictions in your application.
• Batch processing large lists of email addresses asynchronously to normalize them and retrieve MX records for delivery validation.
• Normalizing email addresses in offline mode (skip_dns=True) when DNS lookups are unavailable or undesired.
• Canonicalizing email addresses for user identity matching across systems that may have received them in different formats.

Worth the install?

AI-flagged interpretation of the facts on this page — verify before relying

Normalizes email addresses by detecting the mailbox provider and stripping provider-specific behaviors like plus addressing and period ignoring, with optional async support and DNS-based MX record lookup.

Yes. The package is actively maintained, has no known vulnerabilities, uses a permissive license, and solves a real problem in email handling with low install friction. It's well-suited for applications that need reliable email normalization across multiple providers, especially those requiring async support or batch processing.

Install

email-normalize on PyPI

pip install email-normalize

uv add email-normalize

poetry add email-normalize

Installing email-normalize

Before you install

Low friction installation with only two runtime dependencies (aiodns and tldextract). The package is actively maintained with a recent release and supports current Python versions (3.11+).

License in practice

BSD 3-Clause License is permissive and imposes minimal restrictions on use, modification, and distribution in both open-source and commercial contexts.

Quickstart

pip install email-normalize

import email_normalize

result = email_normalize.normalize('f.o.o+bar@gmail.com')
print(result.normalized_address)  # foo@gmail.com
print(result.mailbox_provider)    # Google

Requires Python 3.11 or later. Runtime dependencies aiodns and tldextract must be installed (handled automatically by pip).

Verify before relying

• Whether aiodns and tldextract have their own security or maintenance concerns that could affect this package's reliability.
• Performance characteristics when processing large batches of addresses with DNS lookups enabled.

Package facts

Evidence: email_normalize-3.2.0-py3-none-any.whl

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