I have Action Mailer setup to render an email using the body attribute of my Email model (in the database). I want to be able to use erb in the body but I can't figure out how to get it to render in the sent email message.

I'm able to get the body as a string with this code

# models/user_mailer.rb
def custom_email(user, email_id)
  email = Email.find(email_id)

  recipients    user.email
  from          "Mail It Example <[email protected]>"
  subject       "Hello From Mail It"
  sent_on       Time.now

  # pulls the email body and passes a string to the template views/user_mailer/customer_email.text.html.erb
  body          :msg => email.body
end

I came across this article http://rails-nutshell.labs.oreilly.com/ch05.html which says I can use render but I'm only able to get render :text to work and not render :inline

# models/user_mailer.rb
def custom_email(user, email_id)
  email = Email.find(email_id)

  recipients    user.email
  from          "Mail It Example <[email protected]>"
  subject       "Hello From Mail It"
  sent_on       Time.now

  # body          :msg => email.body
  body          :msg => (render :text => "Thanks for your order")  # renders text and passes as a variable to the template
  # body          :msg => (render :inline => "We shipped <%= Time.now %>")  # throws a NoMethodError

end