Page 0: Page 1: Email on Rails Allen Fair BIGLIST Inc. Philly on Rails August 6, 2007 Page 2: Email in Rails  ActionMailer   TMail  Creates Email Messages Invokes SMTP or Sendmail for delivery Receives Email Messages for processing Includes updated TMail library  Constructs action messages (outgoing) Parses messages (incoming) Accesses, traverses parts/attachments, headers, etc. Supports most RFC822 and MIME standards      Page 3: Email Review  Mail User Agent (MUA)  Reading and Composition Queuing & Delivery Envelope – Of Interest to your MTA    Mail Transport Agent (MTA)   Email  Return Path – Specfies source/bounce address Recipients – List of addresses to receive the email Headers Simple Body or MIME Multipart Container Attachments and Body Parts  Message – Of interest to your MUA    Page 4: Email Headers  From: User Name <user1@example.com> To: User Name <user2@example.com> Reply-To: <user3@example.com> Subject: [PhillyOnRails] Email on Rails Talk Date: Sat, 04 Aug 2007 14:43:01 -0400 Content-Type: text/plain Received: from smtp.x.com by mail.y.com ... X-*:        Page 5: Three Ways Home  From: allen@example.com ”Allen”    Default ”reply to” address Matches address book for ”safe list” Displayed to user Overrides ”from” address Used by MTA to authenticate sender and returned bounced emails Not used or seen by most mail clients Variable Envelope Return Path (VERP)-Friendly  Reply-To: fair@example.com   Return Path: bounce-user=x.com@y.com    Page 6: Simple text/plain email From: <sender@example.com> To: <recipient@example.com> Subject: Text is plain Date: Tue, 5 Jun 2007 05:58:03 -0400 This is a plain text email. Page 7: MIME Types  text/plain text/html multipart/alternative image/jpeg multipart/mixed multipart/related Stir to combine...       Page 8: Complex Email Message  multipart/mixed – Body and attachments  multipart/alternative – Versions for viewing text/plain – Text version of email body  multipart/related – References positioned images (within HTML body)  text/html – HTML version of email body  image/jpeg – Image embedded inside the HTML body part application/pdf – Some attachment   Page 9: Components of Rails Email  Configuration in environments.rb or environment/*.rb Email Out    Mailer model (ActionMailer::Base) Message body Templates SMTP or IMAP checker Email Controller for direct delivery (procmail, .qmail) Mailer#receive instance method  Email In     Plugins Page 10: ActionMailer Configurations  Set in config/environment* ActionMailer::Base.xxxxxx = value         smtp_settings = {} sendmail_settings={} raise_delivery_errors=false delivery_method=:smtp perform_deliveries=true default_charset=”utf-8” See rdoc for full list.  ActionMailer::Base is well documented! Page 11: ActionMailer::Base Configs  config.action_mailer.raise_delivery_errors = true ActionMailer::Base.delivery_method =   :smtp (default, needs smtp_settings defined) :sendmail (*nix, optional sendmail_settings) :address => "smtp.example.com", :port => 25, :domain => 'www.example.com', :user_name => "user@example.com", :password => ‘mypass’, # no TLS support :authentication => :login }   ActionMailer::Base.smtp_settings = { Page 12: Configuring Sendmail  default:  sendmail -i -t [recipients....] < msg sendmail_settings = { :location=> '/usr/sbin/sendmail', :arguments=> '-i -t'} not good multi-recipient messages SMTP signals . as EOF  In ./config/environment*   -t: read messages for recipient   -i: ignore dots on lines   -f return path (useful for VERP) Page 13: Add Mailer Class to Application $ script/generate mailer UserMailer register password ... exists create exists create create create create create create create app/models/ app/views/user_mailer test/unit/ test/fixtures/user_mailer app/models/user_mailer.rb test/unit/user_mailer_test.rb app/views/user_mailer/register.rhtml test/fixtures/user_mailer/register app/views/user_mailer/password.rhtml test/fixtures/user_mailer/password Page 14: Building the Message # app/models/user_mailer.rb class UserMailer < ActionMailer::Base def register(user, sent_at = Time.now) subject 'Thank you for registering' body :user=>user #instance vars in rhtml recipients user.email from 'admin@example.com' sent_on sent_at headers 'reply-to'=>'support@example.com' end ... end Page 15: Message Body Template <%# app/views/user_mailer/register.rhtml %> <%= @user.name %>, Thanks for registering. Please click the following link to validate your registration and use our application! <%= url_for(:host => "example.com", :controller => "user", :action => "confirm", :id=>@user.id, :code=>@user.confirm_code ) %> Sincerely, mydomain.com Page 16: Sending the email # app/models/user.rb def self.register(info) user = User.create(info) UserMailer.deliver_register(user) end # app/controllers/user_controller.rb def forgot_password @user = User.find_by_email(params[:email]) # Alternate method to create, then deliver the mail tmail = UserMailer.create_password(@user) UserMailer.deliver(tmail) end Page 17: Creating Email in HTML class UserMailer < ActionMailer::Base def register(user, sent_at = Time.now) subject ”Thanks for registering” body :user=>user # instance vars in rhtml recipients user.email from 'admin@example.com' sent_on sent_at headers 'reply-to'=>'support@example.com' content_type "text/html" end ... end Page 18: The HTML Mail Template <%# app/views/user_mailer/register.rhtml %> <p><%= @user.name %>,</p> <p>Thanks for registering. Please click the following link to validate your registration and use our application!</p> <div> <%= url_for(:host => "example.com", :controller => "user", :action => "confirm", :id=>@user.id, :code=>@user.confirm_code ) %> </div> <p>Sincerely,<br /> mydomain.com </p> Page 19: Attachments def signup_notification(recipient) recipients recipient.email_address_with_name subject "New account information" from "admin@example.com" attachment :content_type => "image/jpeg", :body => File.read("an-image.jpg") attachment "application/pdf" do |a| a.body = generate_your_pdf_here() end end Page 20: Multiple Content Types  Implicit with special view name formats:   register.text.plain.rhtml (*.text.plain.erb) register.text.html.rhtml (*.text.html.erb)  Explicit with attaching each part part :content_type => "text/html", :body => render_message("register-as-html", :account => recipient) part "text/plain" do |p| p.body = render_message("register-as-plain", :account => recipient) p.transfer_encoding = "base64" Page 21: Custom Mail with TMail headers={:subject=>”Hello”, ... } text_part = new_body_part(txt, 'text/plain') html_part = new_body_part(html, 'text/html') mail = TMail::Mail.new headers.each {|f,v| mail[f.to_s] = v } mail.mime_encode_multipart(true) mail.content_type = 'multipart/alternative' mail.parts << text_part << html_part UserMailer.deliver(mail) def self.new_body_part(data, ct='text/plain') part = TMail::Mail.new part.body = data part.content_type = ct part end Page 22: Gotchas  Recipients from email headers (sendmail) Use deliver_register(), not register() Not good for mass mailings models with views! Helpers are supported, but not automagically created (app/helpers/user_mailer_helper.rb)      app/helpers/application_helper.rb  Use script/console for debugging Errors/exceptions are silenced by default  Page 23: Receiving Email  POP3 or IMAP  Trigger or Cron process Procmail qmail-local (dot-qmail) sendmail/postfix script/runner (not recommended in production) curl to /controller/action  Local Delivery     Sending to Rails   Page 24: Receive Email via POP3/IMAP require 'net/pop' def self.check_pop # in user_mailer.rb or plugin Net::POP3.start(@@pop_settings[:server], @@pop_settings[:port],@@pop_settings[:user_name], @@pop_settings[:password]) do |pop| if pop.mails.empty? logger.info "NO MAIL" else pop.mails.each do |email| begin new.receive(TMail::Mail.parse(email.pop)) email.delete rescue Exception => e logger.error ... end end end Page 25: Running the POP checks # Place in ./config/environment* class ActionMailer::Base @@pop_settings = {:server=>"mail.comcast.net", :port=> 110, :user_name=>'username', :password=>'secret', } end # model/user_mailer.rb def self.receive_loop(seconds=300, iterations=0) iteration = 1 while true do logger.info "Running Mail Importer..." check_pop logger.info "Finished Mail Importer." return if iteration==iterations iteration += 1 sleep seconds end end Page 26: Directing email to HTTP class EmailController < ApplicationController def receive if params[:mail] UserMailer.receive(params[:mail]) render ”Ok”, :status => HTTP::Status::OK else render "Error: This action is intended to transfer email into the application", :status => HTTP::Status::BAD_REQUEST end end end Page 27: Running the /email/receive action $ curl -F ”mail=<msgfile” \ http://localhost/email/receive Security: ● Can be run from separate email server ● Lock down this url to public ● Scan and drop incoming virus messages ● Scan and drop incoming Spam messages ● Prevent unexpected addresses from being accepted by SMTP (SMTP-Level Rejection) Page 28: Mass Mailings  Send to entire subscriber/registration list  Hide Individual email addresses (To: list@domain) SMTP and sendmail-command recipient limitations Remove bounced addresses Variable Envelope Return Path (VERP)   Monitor bounced emails   Page 29: VERP: Variable Envelope Return Path  Best for automating results from multiple deliveries or mailing lists adds the recipient email address to return path dynamically Supported by many major MTA's Return Path (RP) In: msg-123-@example.com Qmail VERP Ret. Path: user-@host-@[] RP Out: msg-123-user=x.com@example.com      Page 30: Running your own Mail Server?  Anti-Virus – ClamAV, Anti-Spam – Spam Assassin Whitelists – AOL, Yahoo, MSN Feedback Loops – AOL, MSN, Juno, etc. Concurrency Issues – Comcast, BellSouth Certified Email:       Sender Score Certified – MSN, Hotmail Goodmail – AOL, Yahoo  Domain Keys, DK/IM, SPF, DNS-Lookup RBL, SpamCop, Blacklists External SMTP/Delivery Service   Page 31: Recap  Set up configurations for outgoing and incoming email script/generate mailer MyMailer templates... MyMailer.deliver_xxxx() Send email carefully, be a good netizen Process Incoming email via SMTP or HTTP Prepare for Virus, Spam, and other Attacks Thank you!       Page 32: