Hi, I have Exchange 2007 in a lab and I have some problem with free hard disk space, so I can't receive no more messages, because Exchangestops processing mails if there is no enough free space. is it possible to change the amount of free space needed ? Thanks

Yes. There is an .ini file, but for the life of me i can't think of which one it is :-) If you go into the app log you should see a warning message for Hub Transport and if you click the help link it'll tell you what to edit.

The file is the EdgeTransport.exe.config application configuration file that is located in the c:\ProgramFiles\Microsoft\ExchangeServer\Bin directory. For detailed info on it: http://technet.microsoft.com/en-us/library/03003544-e802-4988-9427-5fc4da64dcb8.aspx