The thread window contains the information about currently running threads.

Every line represents on thread. The line contains the threadid (in the format [1234]) followed by the IP number of the foreign mailhost. After that the last received command is shown together with its timestamp. Doubleclicking on a thread gives you information about the history of concerning thread. Every received command with the timestamp is shown then.

The button Active connections shows the currently active server and client threads. The number of client threads can never exceed the number of server connections.
The button Terminate forces to close the currently selected thread.