You can also try some hack advantage scripts embedded in the email, some scripts can be activated when the user opens the email.

Important,before starting an email campaign, you should ask your users when they register or in the settings website page the "do you want to receive notifications, promotions blah blah blah", and also make sure they can "unsubscribe" with a link in your email(you will also can catch user information).

Changing topic, nice pics you have in flickr