Mail is an internet library for Ruby that is designed to handle email generation, parsing and sending in a simple, rubyesque manner.

The purpose of this library is to provide a single point of access to handle all email functions, including sending and receiving email. All network type actions are done through proxy methods to Net::SMTP, Net::POP3 etc.

Built from my experience with TMail, it is designed to be a pure ruby implementation that makes generating, sending and parsing email a no brainer.

It is also designed from the ground up to work with the more modern versions of Ruby. Modern Rubies handle text encodings much more wonderfully than before so these features have been taken full advantage of in this library allowing Mail to handle a lot more messages more cleanly than TMail.

Finally, Mail has been designed with a very simple object oriented system that really opens up the email messages you are parsing, if you know what you are doing, you can fiddle with every last bit of your email directly.

Yes, you! Mail is used in countless apps by people around the world. It is, like all open source software, a labour of love borne from our free time. If you would like to say thanks, please dig in and contribute alongside us! Triage and fix GitHub issues, improve our documentation, add new features—up to you! Thank you for pitching in.

• Compatibility
• Discussion
• Current Capabilities of Mail
• Roadmap
• Testing Policy
• API Policy
• Installation
• Encodings
• Contributing
• Usage
• Excerpts from TREC Spam Corpus 2005
• License

Mail is tested against:

• Ruby: 2.5
• Ruby: 2.6
• Ruby: 2.7
• Ruby: 3.0
• Ruby: 3.1
• Ruby: 3.2
• JRuby: 9.2
• JRuby: 9.3
• JRuby: 9.4
• JRuby: stable
• JRuby: head
• Truffleruby: stable
• Truffleruby: head

As new versions of Ruby are released, Mail will be compatible with support for the "preview" and all "normal maintenance", "security maintenance" and the two most recent "end of life" versions listed at the Ruby Maintenance Branches page. Pull requests to assist in adding support for new preview releases are more than welcome.

Every Mail commit is tested by GitHub Actions on all supported Ruby versions.

If you want to discuss mail with like minded individuals, please subscribe to the Google Group.

• RFC5322 Support, Reading and Writing
• RFC6532 Support, reading UTF-8 headers
• RFC2045-2049 Support for multipart email
• Support for creating multipart alternate email
• Support for reading multipart/report email & getting details from such
• Wrappers for File, Net/POP3, Net/SMTP
• Auto-encoding of non-US-ASCII bodies and header fields

Mail is RFC5322 and RFC6532 compliant now, that is, it can parse US-ASCII and UTF-8 email and generate US-ASCII email. There are a few obsoleted email syntax that it will have problems with, but it also is quite robust, meaning, if it finds something it doesn't understand it will not crash, instead, it will skip the problem and keep parsing. In the case of a header it doesn't understand, it will initialise the header as an optional unstructured field and continue parsing.

This means Mail won't (ever) crunch your data (I think).

You can also create MIME emails. There are helper methods for making a multipart/alternate email for text/plain and text/html (the most common pair) and you can manually create any other type of MIME email.

Next TODO:

• Improve MIME support for character sets in headers, currently works, mostly, needs refinement.

Basically... we do BDD on Mail. No method gets written in Mail without a corresponding or covering spec. We expect as a minimum 100% coverage measured by RCov. While this is not perfect by any measure, it is pretty good. Additionally, all functional tests from TMail are to be passing before the gem gets released.

It also means you can be sure Mail will behave correctly.

You can run tests locally by running bundle exec rspec.

You can run tests on all supported Ruby versions by using act.

No API removals within a single point release. All removals to be deprecated with warnings for at least one MINOR point release before removal.

Also, all private or protected methods to be declared as such - though this is still I/P.

Installation is fairly simple, I host mail on rubygems, so you can just do:

# gem install mail

If you didn't know, handling encodings in Emails is not as straight forward as you would hope.

I have tried to simplify it some:

1. All objects that can render into an email, have an #encoded method. Encoded will return the object as a complete string ready to send in the mail system, that is, it will include the header field and value and CRLF at the end and wrapped as needed.

2. All objects that can render into an email, have a #decoded method. Decoded will return the object's "value" only as a string. This means it will not include the header fields (like 'To:' or 'Subject:').

3. By default, calling #to_s on a container object will call its encoded method, while #to_s on a field object will call its decoded method. So calling #to_s on a Mail object will return the mail, all encoded ready to send, while calling #to_s on the From field or the body will return the decoded value of the object. The header object of Mail is considered a container. If you are in doubt, call #encoded, or #decoded explicitly, this is safer if you are not sure.

4. Structured fields that have parameter values that can be encoded (e.g. Content-Type) will provide decoded parameter values when you call the parameter names as methods against the object.

5. Structured fields that have parameter values that can be encoded (e.g. Content-Type) will provide encoded parameter values when you call the parameter names through the object.parameters['<parameter_name>'] method call.

Please do! Contributing is easy in Mail. Please read the CONTRIBUTING.md document for more info.

All major mail functions should be able to happen from the Mail module. So, you should be able to just require 'mail' to get started.

mail is pretty well documented in its Ruby code. You can look it up e.g. at rubydoc.info.

mail = Mail.new do
  from    '[email protected]'
  to      '[email protected]'
  subject 'This is a test email'
  body    File.read('body.txt')
end

mail.to_s #=> "From: [email protected]\r\nTo: you@...

mail = Mail.new do
  body File.read('body.txt')
end

mail['from'] = '[email protected]'
mail[:to]    = '[email protected]'
mail.subject = 'This is a test email'

mail.header['X-Custom-Header'] = 'custom value'

mail.to_s #=> "From: [email protected]\r\nTo: you@...

mail = Mail.new do
  to   '[email protected]'
  body 'Some simple body'
end

mail.to_s =~ /Message\-ID: <[\d\w_] @. .mail/ #=> 27

Mail will automatically add a Message-ID field if it is missing and give it a unique, random Message-ID along the lines of:

<[email protected]>

mail = Mail.new do
  to         '[email protected]'
  message_id '<[email protected]>'
  body       'Some simple body'
end

mail.to_s =~ /Message\-ID: <[email protected]>/ #=> 27

Mail will take the message_id you assign to it trusting that you know what you are doing.

Mail defaults to sending via SMTP to local host port 25. If you have a sendmail or postfix daemon running on this port, sending email is as easy as:

Mail.deliver do
  from     '[email protected]'
  to       '[email protected]'
  subject  'Here is the image you wanted'
  body     File.read('body.txt')
  add_file '/full/path/to/somefile.png'
end

or

mail = Mail.new do
  from     '[email protected]'
  to       '[email protected]'
  subject  'Here is the image you wanted'
  body     File.read('body.txt')
  add_file :filename => 'somefile.png', :content => File.read('/somefile.png')
end

mail.deliver!

Sending via sendmail can be done like so:

mail = Mail.new do
  from     '[email protected]'
  to       '[email protected]'
  subject  'Here is the image you wanted'
  body     File.read('body.txt')
  add_file :filename => 'somefile.png', :content => File.read('/somefile.png')
end

mail.delivery_method :sendmail

mail.deliver

Sending via smtp (for example to mailcatcher)

Mail.defaults do
  delivery_method :smtp, address: "localhost", port: 1025
end

Exim requires its own delivery manager, and can be used like so:

mail.delivery_method :exim, :location => "/usr/bin/exim"

mail.deliver

Mail may be "delivered" to a logfile, too, for development and testing:

# Delivers by logging the encoded message to $stdout
mail.delivery_method :logger

# Delivers to an existing logger at :debug severity
mail.delivery_method :logger, logger: other_logger, severity: :debug

You can configure Mail to receive email using retriever_method within Mail.defaults:

# e.g. POP3
Mail.defaults do
  retriever_method :pop3, :address    => "pop.gmail.com",
                          :port       => 995,
                          :user_name  => '<username>',
                          :password   => '<password>',
                          :enable_ssl => true
end

# IMAP
Mail.defaults do
  retriever_method :imap, :address    => "imap.mailbox.org",
                          :port       => 993,
                          :user_name  => '<username>',
                          :password   => '<password>',
                          :enable_ssl => true
end

You can access incoming email in a number of ways.

The most recent email:

Mail.all    #=> Returns an array of all emails
Mail.first  #=> Returns the first unread email
Mail.last   #=> Returns the last unread email

The first 10 emails sorted by date in ascending order:

emails = Mail.find(:what => :first, :count => 10, :order => :asc)
emails.length #=> 10

Or even all emails:

emails = Mail.all
emails.length #=> LOTS!

mail = Mail.read('/path/to/message.eml')

mail.envelope_from   #=> '[email protected]'
mail.from.addresses  #=> ['[email protected]', '[email protected]']
mail.sender.address  #=> '[email protected]'
mail.to              #=> '[email protected]'
mail.cc              #=> '[email protected]'
mail.subject         #=> "This is the subject"
mail.date.to_s       #=> '21 Nov 1997 09:55:06 -0600'
mail.message_id      #=> '<[email protected]>'
mail.decoded         #=> 'This is the body of the email...

Many more methods available.

mail = Mail.read('multipart_email')

mail.multipart?          #=> true
mail.parts.length        #=> 2
mail.body.preamble       #=> "Text before the first part"
mail.body.epilogue       #=> "Text after the last part"
mail.parts.map { |p| p.content_type }  #=> ['text/plain', 'application/pdf']
mail.parts.map { |p| p.class }         #=> [Mail::Message, Mail::Message]
mail.parts[0].content_type_parameters  #=> {'charset' => 'ISO-8859-1'}
mail.parts[1].content_type_parameters  #=> {'name' => 'my.pdf'}

Mail generates a tree of parts. Each message has many or no parts. Each part is another message which can have many or no parts.

A message will only have parts if it is a multipart/mixed or multipart/related content type and has a boundary defined.

mail.attachments.each do | attachment |
  # Attachments is an AttachmentsList object containing a
  # number of Part objects
  if (attachment.content_type.start_with?('image/'))
    # extracting images for example...
    filename = attachment.filename
    begin
      File.open(images_dir   filename, "w b", 0644) {|f| f.write attachment.decoded}
    rescue => e
      puts "Unable to save data for #{filename} because #{e.message}"
    end
  end
end

Mail makes some basic assumptions and makes doing the common thing as simple as possible.... (asking a lot from a mail library)

mail = Mail.deliver do
  part :content_type => "multipart/mixed" do |p1|
    p1.part :content_type => "multipart/related" do |p2|
      p2.part :content_type => "multipart/alternative",
              :content_disposition => "inline" do |p3|
        p3.part :content_type => "text/plain; charset=utf-8",
                :body => "Here is the attachment you wanted\n"
        p3.part :content_type => "text/html; charset=utf-8",
                :body => "<h1>Funky Title</h1><p>Here is the attachment you wanted</p>\n"
      end
    end
    add_file '/path/to/myfile.pdf'
  end
  from      "Mikel Lindsaar <[email protected]>"
  to        "[email protected]"
  subject   "First multipart email sent with Mail"
end

Mail then delivers the email at the end of the block and returns the resulting Mail::Message object, which you can then inspect if you so desire...

puts mail.to_s #=>

Date: Tue, 26 Apr 2022 20:12:07  0200
From: Mikel Lindsaar <[email protected]>
To: [email protected]
Message-ID: <[email protected]>
Subject: First multipart email sent with Mail
MIME-Version: 1.0
Content-Type: multipart/mixed;
 boundary=\"--==_mimepart_626835f733867_10873fdfa3c2ffd494636\";
 charset=UTF-8
Content-Transfer-Encoding: 7bit


----==_mimepart_626835f733867_10873fdfa3c2ffd494636
Content-Type: multipart/mixed;
 boundary=\"--==_mimepart_626835f73382a_10873fdfa3c2ffd494518\";
 charset=UTF-8
Content-Transfer-Encoding: 7bit


----==_mimepart_626835f73382a_10873fdfa3c2ffd494518
Content-Type: multipart/related;
 boundary=\"--==_mimepart_626835f7337f5_10873fdfa3c2ffd494438\";
 charset=UTF-8
Content-Transfer-Encoding: 7bit


----==_mimepart_626835f7337f5_10873fdfa3c2ffd494438
Content-Type: multipart/alternative;
 boundary=\"--==_mimepart_626835f733702_10873fdfa3c2ffd494376\";
 charset=UTF-8
Content-Transfer-Encoding: 7bit
Content-Disposition: inline
Content-ID: <[email protected]>


----==_mimepart_626835f733702_10873fdfa3c2ffd494376
Content-Type: text/plain;
 charset=utf-8
Content-Transfer-Encoding: 7bit

Here is the attachment you wanted

----==_mimepart_626835f733702_10873fdfa3c2ffd494376
Content-Type: text/html;
 charset=utf-8
Content-Transfer-Encoding: 7bit

<h1>Funky Title</h1><p>Here is the attachment you wanted</p>

----==_mimepart_626835f733702_10873fdfa3c2ffd494376--

----==_mimepart_626835f7337f5_10873fdfa3c2ffd494438--

----==_mimepart_626835f73382a_10873fdfa3c2ffd494518--

----==_mimepart_626835f733867_10873fdfa3c2ffd494636
Content-Type: text/plain;
 charset=UTF-8;
 filename=myfile.txt
Content-Transfer-Encoding: 7bit
Content-Disposition: attachment;
 filename=myfile.txt
Content-ID: <6
[email protected]>

Hallo,
Test
End

----==_mimepart_626835f733867_10873fdfa3c2ffd494636--

Mail inserts the content transfer encoding, the mime version, the content-IDs and handles the content-type and boundary.

Mail assumes that if your text in the body is only us-ascii, that your transfer encoding is 7bit and it is text/plain. You can override this by explicitly declaring it.

You don't have to use a block with the text and html part included, you can just do it declaratively. However, you need to add Mail::Parts to an email, not Mail::Messages.

mail = Mail.new do
  to      '[email protected]'
  from    'Mikel Lindsaar <[email protected]>'
  subject 'First multipart email sent with Mail'
end

text_part = Mail::Part.new do
  body 'This is plain text'
end

html_part = Mail::Part.new do
  content_type 'text/html; charset=UTF-8'
  body '<h1>This is HTML</h1>'
end

mail.text_part = text_part
mail.html_part = html_part

Results in the same email as done using the block form

@mail = Mail.read('/path/to/bounce_message.eml')

@mail.bounced?         #=> true
@mail.final_recipient  #=> rfc822;[email protected]
@mail.action           #=> failed
@mail.error_status     #=> 5.5.0
@mail.diagnostic_code  #=> smtp;550 Requested action not taken: mailbox unavailable
@mail.retryable?       #=> false

You can just read the file off an absolute path, Mail will try to guess the mime_type and will encode the file in Base64 for you.

@mail = Mail.new
@mail.add_file("/path/to/file.jpg")
@mail.parts.first.attachment? #=> true
@mail.parts.first.content_transfer_encoding.to_s #=> 'base64'
@mail.attachments.first.mime_type #=> 'image/jpg'
@mail.attachments.first.filename #=> 'file.jpg'
@mail.attachments.first.decoded == File.read('/path/to/file.jpg') #=> true

Or You can pass in file_data and give it a filename, again, mail will try and guess the mime_type for you.

@mail = Mail.new
@mail.attachments['myfile.pdf'] = File.read('path/to/myfile.pdf')
@mail.parts.first.attachment? #=> true
@mail.attachments.first.mime_type #=> 'application/pdf'
@mail.attachments.first.decoded == File.read('path/to/myfile.pdf') #=> true

You can also override the guessed MIME media type if you really know better than mail (this should be rarely needed)

@mail = Mail.new
@mail.attachments['myfile.pdf'] = { :mime_type => 'application/x-pdf',
                                    :content => File.read('path/to/myfile.pdf') }
@mail.parts.first.mime_type #=> 'application/x-pdf'

Of course... Mail will round trip an attachment as well

@mail = Mail.new do
  to      '[email protected]'
  from    'Mikel Lindsaar <[email protected]>'
  subject 'First multipart email sent with Mail'

  text_part do
    body 'Here is the attachment you wanted'
  end

  html_part do
    content_type 'text/html; charset=UTF-8'
    body '<h1>Funky Title</h1><p>Here is the attachment you wanted</p>'
  end

  add_file '/path/to/myfile.pdf'
end

@round_tripped_mail = Mail.new(@mail.encoded)

@round_tripped_mail.attachments.length #=> 1
@round_tripped_mail.attachments.first.filename #=> 'myfile.pdf'

See "Testing and extracting attachments" above for more details.

If mail is part of your system, you'll need a way to test it without actually sending emails, the TestMailer can do this for you.

require 'mail'
=> true
Mail.defaults do
  delivery_method :test
end
=> #<Mail::Configuration:0x19345a8 @delivery_method=Mail::TestMailer>
Mail::TestMailer.deliveries
=> []
Mail.deliver do
  to '[email protected]'
  from '[email protected]'
  subject 'testing'
  body 'hello'
end
=> #<Mail::Message:0x19284ec ...
Mail::TestMailer.deliveries.length
=> 1
Mail::TestMailer.deliveries.first
=> #<Mail::Message:0x19284ec ...
Mail::TestMailer.deliveries.clear
=> []

There is also a set of RSpec matchers stolen/inspired by Shoulda's ActionMailer matchers (you'll want to set delivery_method as above too):

Mail.defaults do
  delivery_method :test # in practice you'd do this in spec_helper.rb
end

RSpec.describe "sending an email" do
  include Mail::Matchers

  before(:each) do
    Mail::TestMailer.deliveries.clear

    Mail.deliver do
      to ['[email protected]', '[email protected]']
      from '[email protected]'
      subject 'testing'
      body 'hello'
    end
  end

  it { is_expected.to have_sent_email } # passes if any email at all was sent

  it { is_expected.to have_sent_email.from('[email protected]') }
  it { is_expected.to have_sent_email.to('[email protected]') }

  # can specify a list of recipients...
  it { is_expected.to have_sent_email.to(['[email protected]', '[email protected]']) }

  # ...or chain recipients together
  it { is_expected.to have_sent_email.to('[email protected]').to('[email protected]') }

  it { is_expected.to have_sent_email.with_subject('testing') }

  it { is_expected.to have_sent_email.with_body('hello') }

  # Can match subject or body with a regex
  # (or anything that responds_to? :match)

  it { is_expected.to have_sent_email.matching_subject(/test(ing)?/) }
  it { is_expected.to have_sent_email.matching_body(/h(a|e)llo/) }

  # Can chain together modifiers
  # Note that apart from recipients, repeating a modifier overwrites old value.

  it { is_expected.to have_sent_email.from('[email protected]').to('[email protected]').matching_body(/hell/)

  # test for attachments

  # ... by specific attachment
  it { is_expected.to have_sent_email.with_attachments(my_attachment) }

  # ... or any attachment
  it { is_expected.to have_sent_email.with_attachments(any_attachment) }

  # ... or attachment with filename
  it { is_expected.to have_sent_email.with_attachments(an_attachment_with_filename('file.txt')) }

  # ... or attachment with mime_type
  it { is_expected.to have_sent_email.with_attachments(an_attachment_with_mime_type('application/pdf')) }

  # ... by array of attachments
  it { is_expected.to have_sent_email.with_attachments([my_attachment1, my_attachment2]) } #note that order is important

  #... by presence
  it { is_expected.to have_sent_email.with_any_attachments }

  #... or by absence
  it { is_expected.to have_sent_email.with_no_attachments }

end

The spec fixture files in spec/fixtures/emails/from_trec_2005 are from the 2005 TREC Public Spam Corpus. They remain copyrighted under the terms of that project and license agreement. They are used in this project to verify and describe the development of this email parser implementation.

http://plg.uwaterloo.ca/~gvcormac/treccorpus/

They are used as allowed by 'Permitted Uses, Clause 3':

"Small excerpts of the information may be displayed to others
 or published in a scientific or technical context, solely for
 the purpose of describing the research and development and
 related issues."

 -- http://plg.uwaterloo.ca/~gvcormac/treccorpus/

(The MIT License)

Copyright (c) 2009-2016 Mikel Lindsaar

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the 'Software'), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.