As of 2020, Mailchimp has an official gem for this: https://rubygems.org/gems/MailchimpTransactional
As of June 2023, this mandrill-api gem is working (and we are still using it), but I don't know how long that will stay true.
On June 3, 2025, in an attempt to resolve a warning github was showing, I accidentally wiped the history by clicking on "discard 8 commits". I had a local backup, so I cherry-picked them, but the timestamps of the commits are no longer valid. The first 3 were 2017, the next 2 2020, the next 2 2023, and the last 1 2025
mandrill-api-ruby is a fork of mandrill-api gem (src) with uptodate dependencies.
Original code here: https://bitbucket.org/mailchimp/mandrill-api-ruby/
Thanks to https://github.com/stellaservice/mandrill-api-ruby for fixing the json dependency.
in your Gemfile change
gem 'mandrill-api'
to
gem 'mandrill-api-json'
and run bundle install
In order to retrieve Mandrill attachments in test mode the following script can be used:
require 'mandrill'
require 'base64'
def extract_attachments(email)
attachments = []
email['attachments'].each do |attachment|
attachment_data = attachment['content']
file_name = attachment['name']
content_type = attachment['type']
# Decode the attachment data from base64
decoded_data = Base64.decode64(attachment_data)
# Save the attachment to a file
File.open(file_name, 'wb') do |file|
file.write(decoded_data)
end
attachments << {
file_name: file_name,
content_type: content_type
}
end
attachments
end
# Mandrill API key
mandrill_api_key = 'YOUR_MANDRILL_API_KEY'
# Mandrill message ID of the delivered email.
# You can find it in https://mandrillapp.com/settings/api, within the request of the email sent.
message_id = 'YOUR_DELIVERED_EMAIL_MESSAGE_ID'
# Initialize Mandrill client
mandrill = Mandrill::API.new(mandrill_api_key)
# Retrieve the message content using Mandrill API
message_info = mandrill.messages.content(message_id)
# Extract attachments from the message
attachments = extract_attachments(message_info)
# Print the extracted attachments
attachments.each do |attachment|
puts "Attachment: #{attachment[:file_name]}"
puts "Content Type: #{attachment[:content_type]}"
puts "---"
end