If you don't want to receive any more mailings from Coderanch, it is mighty easy to unsubscribe!
Depending on the mode chosen by you at the time of JournalSubscribe, you may choose to unsubscribe using the following
Log in to your account at the forums and edit your profile by clicking the "My profile" link. On the "My profile" page, click on the Preferences section to open the settings and change the selection "May JavaRanch send you occasional email notices such as our newsletter and contest announcements?" to "No". Please note that this will also unsubscribe you from any other communication that coderanch sends you, eg: Book Promotion emails.
Specify your email id (on which you are receiving the emails, beware of auto-forwards you may have setup) here.