Thursday, March 29, 2012

Opening Suspicious Emails

Under this heading, I could almost start a topic on urban Myths. The internet abounds with Furhpys  about email, and one of the most common is that something disastrous is going to happen if you open that suspicious email you just received.


This is one of those urban myths that has been around for years that actually has a grain of truth attached to it.  In relation to Thunderbird is is basically a mistruth.  However if you are using a mail client from the Microsoft Stable it is in fact a very real risk.  This is because the Mozilla mail client is designed from the ground up with security in mind, where as the Microsoft product (as well as many others I am sure) are designed with ease of use and a glorious and rich email experience as the single most important thrust.  The trouble with this approach is that almost everything you do to your email to make it sing and dance reduces the security of the email process significantly.

To protect you from those with malicious intent, Thunderbird does not allow any scripts (VBscript JavaScript) to run within the email.  This means that the bouncing ball or the funny banner that the sender programs to follow your mouse simply will not work, but it also means that the folks over at virii R us can't get their little gem to play either, so even if the mail contains a script to download every know virus onto your computer, opening the email will do nothing because the script simply can't run.

This is also the case with Flash animations and flash movies.  They also don't work, and for the same reason that the scripts are disabled. They represent a threat to your security.

Unfortunately this does at times catch other legitimate processes, such as the little Plus and Minus that some emailers include with reports.  In my opinion however the negatives are vastly outweighed by the positives.

Remote Content.

Thunderbird likewise blocks remote images from those not in your address book.  This causes many to moan about the fact that they have to make a conscious decision to 'allow remote content'. I have even seen what I would consider rants about how you don't have to do this in Outlook so why should I have to do it in Thunderbird.  The answer remains the same as it has always been.  Remote content can and does represent a security and privacy risk to you and the recipient of the mail.  You will find that many commercial emails you receive (those ones you subscribed to from XYX newservice, paypal etc) contain a special image just for you.  These images are usually a single pixel and the same color as the background of the mail so they add nothing to the content as such, but the link that downloads that image contains your personal identifiable information.  The result is that the sender can identify that you received the mail they sent and that you opened it, what time of day you opened it and to a reasonable extent where you were when you opened that mail.  Just how close to the were, you can get from here   That web site uses the same technology to locate you are is used with these one pixel images.

Now this blocking of remote content can be turned off, by changing a setting in the config editor.
Tools menu > options > advanced > general and click the config editor button.
Acknowledge the half tongue in cheek warning and enter the editor.
Type mailnews.message_display.disable_remote_image or as much of it as is needed to display it in the list
Double click the entry in the list
Set the value to false

A far more responsible way to do this is to set up a list of domains that can sent you emails with remote content.  (The domain is the part after the @ in an email address).

The procedure is the same as outlined about, but instead of editing mailnews.message_display.disable_remote_image you edit mail.trusteddomains (if the entry does not exist, simply add it.) and include the domain you think you can trust.  This example uses domains I would not trust.,,,,,

If you were to enter that list into the mail.trusteddomains preference all remote content from people that have email addresses at those domains would be show.  Note there are no spaces between entries.

Remember that once you allow remote content by default you are giving up some of your privacy for the convenience of not having to decide if you really need to see the pictures.

My remote content is enabled on a per user basis and I am providing this information as just that. I do not recommend automatic enabling of remote content.  My theory is that if I don't want them in my address book (thus enabling remote content) I probably don't need their images either. I do occasionally click that little allow remote content button to allow remote images, but I decide case by case.


 In the absence of any scripting language support and without the avenue of remote content, that email in your inbox is basically quarantined.  Now all things are void if you open any attachment that the mail has, but the mail itself can do no harm because all of it's attack vectors have need closed off from it.

You can still open a virus in an attachment, but it requires you to make the conscious decision to open the attachment. So the risk of opening a mail is almost nil.  I will not say Zero, because there is nothing in computing that is that certain.


 Looks like religious web sites are riskier than porn sites

Sunday, March 25, 2012

Your email- Your way :- Customize Thunderbird

I remember hearing once that this was one of a catch phrases used with Thunderbird. "Your mail,your way".

The only problem with this phrase is that while Thunderbird is vastly customizable most people are unaware of the basics of the process.   The support forums have seen many an unhappy camper since the Aero Theme was introduced as default, but it is only one Theme and Thunderbirds appearance is customizable with hundreds, if not Thousands of Themes.


The following are four Thunderbird themes which can simply replace the appearance Mozilla gives to Thunderbird

The best approach to get a theme is to use the add-on manager on the tools menu.  When it opens the tab should by default show the get add-ons tag.  If it does not click on the get add-ons. By searching through the Themes this way you get to simply click the install button.  If you do it using your browser, you have to download the files and manually install it. You also get the benefit of only seeing Themes that are compatible with your version of Thunderbird.  This can save time if you are one the current version, but can cause a few problems occasionally if the Thunderbird version is not up to date. Sometime it limits results a little to aggressively.

Additional Functionality

Before you ask for new functionality, check out the add-ons site. it is the official repository of addons for Thunderbird. This site contains hundreds nay Thousands of addons most of which add useful functionality of some sort to Thunderbird.  Simply because there are so many add-ons, the site contains collections.  These are groups of add-ons that users have collected together as they feel they make a set.  I have a collection of the add-ons that get refered to often on the support site at Get Satisfaction. If you are looking for a place to start, there is a chance I have included it in my collection.

One thing to be sure about is that the addon site is not the only place you can get addons. One place I constantly recommend is Kaosmos website This is the home page of some of the best add-ons for Thunderbird. In particular, have a look at the quote and compose manager.  A must have for everyone as it has an option to stabilize the font when composing a message. Without it the font you have selected keeps changing as you move around in the message you are writing.

Remember, that add-ons at the official site are reviewed.  Keasmos also is also a site that can be trusted but it is possible that an add-on can be harmful, so be sure when installing add-ons from sites other than these two that you read what other people have to say about the add-on.  Also be particularly careful of add-ons installed by anti virus and SPAM software. While these are not intentionally harmful, they often break other functionality in Thunderbird.