Converting External CSS to Inline CSS for Mail in Rails

Question

I am trying to create an application that will send out style-heavy emails and have required clients working except Google's Gmail. I researched the issue and it looks like Gmail strips out CSS from external files or CSS nested in the 'style' tag. Does an easy way exist of moving style from an external file to being inline?

Something that will take:

<style>
.wide { width: 100px; }
.cell { display: block; }
</style>
<span class="wide cell">Sample</span>

And convert it to:

<div class="wide cell" style="width: 100px; display: block;">Sample</div>

Thanks!

Answer 1

Here are couple of gems you can check out:

• premailer or premailer-rails for rails
• mail_style
• premailer plus (fork of the above version)
• awesome_email
• roadie

I have no winner at the time writing this answer but premailer seems to be most up-to-date.

Answer 2

Added premailer:

def premailer(message)
  message.text_part.body = Premailer.new(message.text_part.body.to_s, with_html_string: true).to_plain_text
  message.html_part.body = Premailer.new(message.html_part.body.to_s, with_html_string: true).to_inline_css

  return message
end

def welcome(user)
  @user = user

  message = mail ...
end