Sebastian recommended the HTML Temp add-on for the Thunderbird email client to switch HTML messages in Thunderbird on or off more effortlessly.

Download HTML Temp from the official Thunderbird add-ons repository. Once it has been downloaded open up the email client and click on Tools > Add-ons to open the add-ons manager. Click on the options icon on the left of the search all add-ons form there and select Install Add-on from file from the context menu.

Select the downloaded add-on on your local computer and install it in the email program. You need to restart Thunderbird before it becomes available.

The add-on adds the current message display preference in the lower right corner of the status bar. You can now right-click on it to switch to Simple HTML or Original HTML whenever you need to view a message in HTML. Once you are done you use the same method to switch back to plain text messages.

The add-on allows you to move a button with the same functionality to one of the toolbars. This can be helpful if you have disabled the status bar in the program or prefer to click on the button in the header area of the email client.

Update: Sebastian mentioned that the toolbar button behaves different from the status bar button. When you click the toolbar button HTML will be enabled only for the active email and no other. This means that you do not have to click again to restore the plain text message view.

Email On Acid is such a email marketing service. Users can use it to simulate sending out and receiving emails in its interface. The major benefit of this service is that the email marketer (or webmaster who is sending out newsletters) can fully test the newsletter in various email clients including Gmail, Yahoo Mail, Thunderbird, Microsoft Outlook or Windows Mail without leaving the website once.

The marketing emails can be added as urls or pasted with their html code. Email on Acid will then parse the email and display a tabbed interface that is displaying the email in the various email clients and services.

HTML emails are displayed by default. It is possible to switch to text mode which simulates the email in clients that do not support html or have html emails disabled. The email marketing service will also perform a code analysis of the html code. Code that is not supported by html emails is displayed in red which can be used to quickly fix html emails before they are send out.

Users who want to make use of Email On Acid need to create a free account at the website.

via Instant Fundas

The main problem that arises when using the Word HTML rendering engine is that Microsoft Outlook 2010 will not support web standards like CSS or background images. This could very well mean that Outlook 2010 users will be stuck with broken HTML emails for the next years after the release. Below is an image that is showing a HTML email in both Microsoft Outlook 2000 and Outlook 2010:

Microsoft Outlook 2000 was using the Internet Explorer rendering engine to display HTML emails. Microsoft mentions benefits that Outlook users gain by using Microsoft Word as their email authoring tool which include automatic styles and templates and SmartArt among other benefits. It would also not be in the best interest performance wise to use a different rendering engine for the display of HTML emails. (via Email Standards)

The initiators of the Fix Outlook protest website are making use of Twitter to rally protesters from all over the world. Every Twitter user that mentions fixoutlook.org in their tweets will automatically partake in the protest. The avatar icons of users will be displayed on the Fix Outlook website. Currently more than 15500 users have already joined the protest.

Rediff has announced a new product that is promising to be an alternative. It is basically an email service that can send back html emails to the user. The user initiates the process in his email client by sending a specifically crafted email to the WebinMail service which will render the requested webpage and send it back to the email account as a html email.

WebinMail states that the service is currently only working in Microsoft Outlook or Blackberry devices but it did work fine in Mozilla Thunderbird as well and might work fine in most email clients supporting html messages.

All that needs to be done to initiate the connection is to send an email to browse@webinmail.com with an url in the subject line (e.g. www.ghacks.net)

The process is not in realtime obviously which is also the greatest flaw of it. It took a few minutes before the html email arrived in the inbox. This is excellent for viewing specific pages on a website but not the prime solution for surfing many pages of blocked websites.

The subject line can contain other parameters as well, they are:

• google:query
• googleimg:query
• rediff:query

All three will perform a search for the query entered by the user and return the results in a html mail.