RFC-5321 (Envelope) email address parser

Usage no npm install needed!

<script type="module">
  import addressRfc2821 from '';


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Parser for RFC-821/RFC-2821/RFC-5321 (envelope) format email addresses (Mailbox and Path).

This module parses email addresses from the SMTP envelope. These are the portions immediately following the SMTP verbs MAIL FROM: and RCPT TO:. RFC-5321 email addesses look like this:

<>             // null
<"quoted string">

To parse email addresses contained in the message headers (To: From: BCC, CC), look instead at an RFC 2822/5322 parser such as address-rfc2822 or email-addresses.


npm install address-rfc2821


const Address = require('address-rfc2821').Address;

const parsed = new Address('<>');

Address Object

The Address object is an interface to reading email addresses passed in at SMTP time. It parses all the formats in RFC-2821 and 2822, as well as UTF8 email addresses according to the RFCs 5890, 5891 and 5892 providing the domain in punycode when encountered It also supports correctly escaping email addresses.


  • new Address (user, host)

Create a new address object for user@host

  • new Address (email)

Creates a new address object by parsing the email address. Will throw an exception if the address cannot be parsed.

  • address.user

Access the local part of the email address


Access the domain part of the email address, decoded if necessary to punycode

  • address.original_host

Access the domain part of the email address, unencoded and case preserved

  • address.format(use_punycode=false)

Provides the email address in the appropriate <user@host> format. And deals correctly with the null sender and local names.

If use_punycode = true, uses instead of address.original_host.

  • address.toString()

Same as format().

  • address.address(newval=null, use_punycode=false)

Provides the email address in 'user@host' format.

If use_punycode = true, uses instead of address.original_host.


This module is MIT licensed.