Two thumb rules in avoiding spam (in your Hotmail inbox) are:
1. Do not open suspicious mails.
2. Do not unsubscribe.
Opening (eg. included images, hence loading them from tracking servers) and unsubscribing is just the same as telling spammers your e-mail address is still being used. However, you can not always label a message spam or not without reading it. That"s why MSN"s Hotmail presents you with a new option (Options > Mail Display Settings > Display Internet Images) to block html images by default. The option is described as:
"To protect your e-mail address from people who send junk mail, you have the option to filter images from e-mail messages until you are sure they are not junk mail. Select whether you want to display images automatically, or review messages before choosing to display the images."
By enabling the protection, you get gray zones instead of pictures. They"re not removed from the mail, but you have to manually open them first before they load. This sure is bad news for mailinglists, customer relationship and opt-in marketing. Of course (in an attempt to monopolise the e-mail market?) images sent by Microsoft seem to by-pass the filter.