I´ve found the solution myself ... in the ChangeLog it sais that with version 5.2.1 "EXITCODE checking for vdelivermail" has been put in and I´m currently using 5.2 :(
So forget about my question, please give me an answer for this one:
Is it save to upgrade from 5.2 to 5.2.1 on an running system? Is there anything I should be aware of or is it just backuping the /bin/ directory and just making the ./configure & make & make-install ?
Just before you do the upgrade, shut down the install, upgrade and restart :).