pipe to cmd in aliases

[Sebastian Rode]

Hello,

i am trying to set up email2trac on a kolab managed domain. The default
configuration of email2trac is to use a pipe to command entry in the
aliases file. Unfortunately, the pipe command is not executed nut
checked against the user database and rejected as invalid. 

If I add receive_override_options=no_address_mappings to the config, the
pipe command works but the canonical address mapping is disabled, so the
normal user accounts are not working at all.

Any hints how to get pipe to command working?

Thanks a lot
Sebastian