Address Book Server allows you to share your contacts and calendar events with others connected to your network or over the Internet. Each participant synchronizes their contacts with the server hosted on your own system. Address Book Server supports the full Address Book and iCal schema. The server also provides a friendly Web interface and an iPhone client which let you access your contact details remotely.
QP2M is an Peer2Mail application, which means that it lets you share, store, and manage your files via email accounts. It work similar to other Peer2Mail applications, but it makes upload and download very simple, and has some unique features. You can upload and download multiple files simultaneously, manage your email accounts, and resume transfers after closing the application.
xstress is a small yet powerful tool to stress test SMTP mail servers. xstress creates multiple threads and sends mail messages with varying subjects, "to" addresses, and body texts. Mail attachments are supported. All the parameters are highly configurable. For example, you can configure the number of threads xstress creates, SMTP timeout, attachment files, "to" address, "from" address, etc.