Rails mailer mimepart visible as text in message body - html

Question

I'm sending test mail using ActionMailer. The template is being rendered and mail is being delivered fine. The only problem is the mimepart and other header data is displayed by Google in message body.
Here is the code that mails..
def testing
mail(:to => "apoorvparijat#gmail.com",:subject => "html mailer", :content_type => "text/html") do |format|
format.html { render 'testing' }
format.text { render :text => "bing" }
end
end
and Here's the email received.
----==_mimepart_508fd46252b8c_8023fe595835ad0479a6 Date: Tue, 30 Oct 2012 18:51:38 +0530
Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit
Content-ID: <508fd46254ea7_8023fe595835ad0480b8#Apoorv-Parijats-MacBook-Pro-2.local.mail>
bing ----==_mimepart_508fd46252b8c_8023fe595835ad0479a6 Date: Tue, 30 Oct 2012 18:51:38
+0530 Mime-Version: 1.0 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding:
7bit Content-ID: <508fd46256465_8023fe595835ad04819c#Apoorv-Parijats-MacBook-Pro-
2.local.mail> Hi bing
column 1 column 2
----==_mimepart_508fd46252b8c_8023fe595835ad0479a6--
Output of the console -
Loading development environment (Rails 3.2.2)
1.9.3-p125 :001 > RankMailer.testing.deliver
I, [2012-10-30T18:51:38.331238 #2050] INFO -- : Rendered rank_mailer/testing.html.erb
(1.8ms)
I, [2012-10-30T18:51:38.333117 #2050] INFO -- : Rendered text template (0.0ms)
I, [2012-10-30T18:51:45.824962 #2050] INFO -- :
Sent mail to apoorvparijat#gmail.com (7484ms)
D, [2012-10-30T18:51:45.825125 #2050] DEBUG -- : Date: Tue, 30 Oct 2012 18:51:38 +0530
From: admin#rankdemon.com
To: apoorvparijat#gmail.com
Message-ID: <508fd462572ec_8023fe595835ad0482c0#Apoorv-Parijats-MacBook-Pro-2.local.mail>
Subject: html mailer
Mime-Version: 1.0
Content-Type: text/html;
charset=UTF-8
Content-Transfer-Encoding: 7bit
----==_mimepart_508fd46252b8c_8023fe595835ad0479a6
Date: Tue, 30 Oct 2012 18:51:38 +0530
Mime-Version: 1.0
Content-Type: text/plain;
charset=UTF-8
Content-Transfer-Encoding: 7bit
Content-ID: <508fd46254ea7_8023fe595835ad0480b8#Apoorv-Parijats-MacBook-Pro-2.local.mail>
bing
----==_mimepart_508fd46252b8c_8023fe595835ad0479a6
Date: Tue, 30 Oct 2012 18:51:38 +0530
Mime-Version: 1.0
Content-Type: text/html;
charset=UTF-8
Content-Transfer-Encoding: 7bit
Content-ID: <508fd46256465_8023fe595835ad04819c#Apoorv-Parijats-MacBook-Pro-2.local.mail>
Hi bing
<table style="border:1px solid red">
<tr>
<td>column 1</td>
<td>column 2</td>
</tr>
</table>
----==_mimepart_508fd46252b8c_8023fe595835ad0479a6--
=> #<Mail::Message:70255316899740, Multipart: false, Headers: <Date: Tue, 30 Oct 2012 18:51:38 +0530>, <From: admin#rankdemon.com>, <To: apoorvparijat#gmail.com>, <Message-ID: <508fd462572ec_8023fe595835ad0482c0#Apoorv-Parijats-MacBook-Pro-2.local.mail>>, <Subject: html mailer>, <Mime-Version: 1.0>, <Content-Type: text/html>, <Content-Transfer-Encoding: 7bit>>

Answer 1

Don't specify :content_type => "text/html" in your mail method. Since you're using format block, rails will automatically pick up mime type.
MORE DETAILS:
Try this to send out multipart email (ie. both html and text formats of email). Notice the order of formats.
mail(:to => "apoorvparijat#gmail.com", :subject => "html mailer") do |format|
format.text { render :text => "bing" }
format.html { render 'testing' }
end