Not only does it automatically mark your email as important, but it prevents my spam filters from marking your mail as spam.
Spam Bots and email address harvesting:
I have had my email address for a long time, and about 90% of my inbox is spam. I have concluded that the best way I can stop the Spam Bots from continuing to harvest my email address is to use an image with my email address on it. This means no link to my email, so you will have to manually type it in. Thank you for understanding.