Switching from Postmark to Postfix - ruby-on-rails

Question

We want to switch from Postmark to Postfix, but with Postfix the mail with the attachment(PDF file) is arriving as garbage:
Date: Sun, 10 Apr 2016 13:17:56 +0300
Mime-Version: 1.0
Content-Type: application/pdf; charset=UTF-8; filename=test_order1460278254278.pdf
Content-Transfer-Encoding: base64
Content-Disposition: attachment; filename=test_order1460278254278.pdf
Content-ID: <570a2854317a9_1c6f12f77f841854#app1.mail>
JVBERi0xLjQKJeLjz9MKNSAwIG9iago8PC9CYXNlRm9udC9QV1dNR1QrQXJp
YWxNVC9EZXNjZW5kYW50Rm9udHNbNiAwIFJdL1R5cGUvRm9udC9TdWJ0eXBl
L1R5cGUwL0VuY29kaW5nL0lkZW50aXR5LUgvVG9Vbmljb2RlIDkgMCBSPj4K
ZW5kb2JqCjEwIDAgb2JqCjw8L0Jhc2VGb250L1dYSkRSSytMdWNpZGFTYW5z
LVR5cGV3cml0ZXJCb2xkL0Rlc2NlbmRhbnRGb250c1sxMSAwIFJdL1R5cGUv
Rm9udC9TdWJ0eXBlL1R5cGUwL0VuY29kaW5nL0lkZW50aXR5LUgvVG9Vbmlj
b2RlIDE0IDAgUj4+CmVuZG9iagoxNSAwIG9iago8PC9CYXNlRm9udC9UaW1l
This is my code:
class UserMailer < ActionMailer::Base
default :from => "mailer#xodapp1.com"
default :bcc => "do_not_reply#xodapp1.com"
default :reply_to => "do_not_reply#xodapp1.com"
def send_email(agent, customer, subject, body, mail_to = nil, mail_cc = nil, url_attachment = nil , name_attachment = nil)
#attachments[name_attachment] = {:content => open(url_attachment).read, :mime_type => MIME::Types.type_for(name_attachment).first} unless url_attachment.nil?
mail_to = !mail_to.nil? ? mail_to : "\"#{customer.name}\" <#{customer.email}>"
mailers_to = mail_to.split(',')
mail_cc = !mail_cc.nil? ? mail_cc.split(',') : agent.email
if [nil, []].include?(mail_cc)
mail_cc = UserMailer.default[:bcc]
end
body = "Copy attached" if body.nil? || body.empty?
mail_obj = mail(:to => mailers_to,
:from => "\"#{agent.name}\" <mailer#xodapp1.com>",
:bcc => mail_cc,
:subject => subject,
:content_type => "text/html",
:body => body.html_safe,
:reply_to => "#{!agent.email.nil? ? agent.email : UserMailer.default[:reply_to]}"
)
mail_obj.attachments[name_attachment] = open(url_attachment).read unless url_attachment.nil?
return mail_obj
end
end

Answer 1

I remove the content_type and change the order:
class UserMailer < ActionMailer::Base
default :from => "mailer#cavsystems.com"
default :bcc => "do_not_reply#cavsystems.com"
default :reply_to => "do_not_reply#cavsystems.com"
def send_email(agent, customer, subject, body, mail_to = nil, mail_cc = nil, url_attachment = nil , name_attachment = nil)
#attachments[name_attachment] = {:content => open(url_attachment).read, :mime_type => MIME::Types.type_for(name_attachment).first} unless url_attachment.nil?
mail_to = !mail_to.nil? ? mail_to : "\"#{customer.name}\" <#{customer.email}>"
mailers_to = mail_to.split(',')
mail_cc = !mail_cc.nil? ? mail_cc.split(',') : agent.email
if [nil, []].include?(mail_cc)
mail_cc = UserMailer.default[:bcc]
end
body = "Copy attached" if body.nil? || body.empty?
attachments[name_attachment] = open(url_attachment).read unless url_attachment.nil?
mail(:to => mailers_to,
:from => "\"#{agent.name}\" <mailer#cavsystems.com>",
:bcc => mail_cc,
:subject => subject,
#:content_type => "text/html",
:body => body.html_safe,
:reply_to => "#{!agent.email.nil? ? agent.email : UserMailer.default[:reply_to]}"
)
#mail_obj.attachments[name_attachment] = open(url_attachment).read unless url_attachment.nil?
#return mail_obj
end
end
Now the email is arriving with the pdf attachment but the HTML code is raw :-(
It's o.k. because we need the pdf not the html.
It will be great if the HTML will be visible.