My b2evolution Version: Not Entered

When i'm trying to post a article by mail, it goes wrong. :roll:
Through the test of the control panel, everything seems fine (Success), but i notice following at the end:

An unexpected error has occurred!
If this error persists, please report it to the administrator

Extra information on this problem
[b]Requested Chapter does not exist![/b]

Any idea what's going wrong?

The format of my mail is:

To: something@domainie.cou
Subject: ProWord: My Titel
Text: MyLogin:MyPassword
My text to typ something to see if it works.