Michal Trojnara wrote:

Obviously private key encryption should not be used in inetd mode. It works fine in daemon mode and on Win32 platform.

Yes, but only when stunnel is started manually. When started automatically on system boot, there is usually nobody present to enter the password of the encrypted private key (except when the key is stored somewhere and its input provided by some script or program - again a security hole). This is not a special problem of stunnel but of all SSL-using servers.