I thought Skype only stores the last 30 days of data on their servers, while it will store every piece of data received on your local computer indefinitely (unless you delete it, of course).
No. I personally have a video message that is almost 3 years old that I've tried to delete multiple times over the years and it still shows up if I do a fresh install of Skype on a new computer.
Very old voice messages are also accessible even if "deleted".
Text chats do seem to disappear, but at this point I don't believe anything Skype says. I figure they keep the chats forever as well.
Chats are definitely saved, but files aren't. You can't retrieve files after certain amount of time. I can also retrieve conversation from 3+ years ago. I don't remember if there is an option to forget conversation history though.
cantrevealname|9 years ago
Very old voice messages are also accessible even if "deleted".
Text chats do seem to disappear, but at this point I don't believe anything Skype says. I figure they keep the chats forever as well.
yeukhon|9 years ago