OK, Stable but all versions up to V 3.6.4 it loose mail since the past 3 years. The mail that is incoming is lost if the internet connection goes down during the mail downloading process. I have searched internet, but there is no documentation on how to recover that lost mail. This bug has existed since they started using the MAILDIR format. Its strange that such an important program should have such a large, unsolved bug like this. I think the problem is related to viewing the messages stored locally.