The Message-ID
as specified by rfc822 is supposed to be a unique identifier for that individual email. That makes it an ideal tracking token for debugging and forensics, just like X-Request-Id
does for web request.
If an inbound email does not, against the rfc822 mandate, specify a Message-ID, one will be generated using the approach from Mail::MessageIdField
.
# File actionmailbox/app/models/action_mailbox/inbound_email/message_id.rb, line 16 def create_and_extract_message_id!(source, **options) message_checksum = OpenSSL::Digest::SHA1.hexdigest(source) message_id = extract_message_id(source) || generate_missing_message_id(message_checksum) create! raw_email: create_and_upload_raw_email!(source), message_id: message_id, message_checksum: message_checksum, **options rescue ActiveRecord::RecordNotUnique nil end
Create a new InboundEmail
from the raw source
of the email, which is uploaded as an Active Storage attachment called raw_email
. Before the upload, extract the Message-ID from the source
and set it as an attribute on the new InboundEmail
.
# File actionmailbox/app/models/action_mailbox/inbound_email/message_id.rb, line 37 def create_and_upload_raw_email!(source) ActiveStorage::Blob.create_and_upload! io: StringIO.new(source), filename: "message.eml", content_type: "message/rfc822", service_name: ActionMailbox.storage_service end
# File actionmailbox/app/models/action_mailbox/inbound_email/message_id.rb, line 27 def extract_message_id(source) Mail.from_source(source).message_id rescue nil end
# File actionmailbox/app/models/action_mailbox/inbound_email/message_id.rb, line 31 def generate_missing_message_id(message_checksum) Mail::MessageIdField.new("<#{message_checksum}@#{::Socket.gethostname}.mail>").message_id.tap do |message_id| logger.warn "Message-ID couldn't be parsed or is missing. Generated a new Message-ID: #{message_id}" end end
© 2004–2021 David Heinemeier Hansson
Licensed under the MIT License.