POPFile is certainly one of the best tools against Spam. You will determine the type of file you do not want to receive, and next time the program will automatically delete it. This way you will "train" the software not to receive certain messages.
Pegasus Mail Free, secure and easy-to-use email client.
POP Peeper Software that runs on the taskbar and notifies you of the arrival of new emails.
NK2Edit Utility that allows you to make changes to your Outlook email list, more precisely in the Autocomplete feature.
Howard Email Notifier Free software for Windows that allows you to monitor multiple email accounts, receive desktop notifications, organize messages into folders and send emails directly from the application.
OutlookStatView Utility that displays statistics about who you communicate with through Outlook.