Skype for Mac OS X

• Improving sound quality
• Skype Quickfilter
• Skype Speed-Dial
• Import contacts
• Bookmark chats
• Privacy settings
• History
• Mood messages
• Send contacts

Privacy settings

If you receive chat messages or calls from people you don’t know you may need to change your Skype privacy setting. You can change your privacy settings in Skype to only allow calls or chats from people in your Contact List who you have authorized.

Go to: “Skype” > “Preferences” > “Privacy”. Check the box next to the option “Only people whom I have authorized”.

Then random strangers and people who are not on your contact list cannot contact you anymore.