Unable to submit case attributes via mailhandler

I have only one project with project_number 100.

Mailhandler is set up like sugested in documentation:
project_number: 100
type: casetracker_basic_case
assign_to: admin
case_status: open
case_priority: 1-high
case_type: bug

When i send an email to mailhandler mailbox it generates a case node but it ignores project_number and other case attributes.

the mailhandler ganerated cases look like this:

Case number: -11
Project:
Opened by: admin
Status:
Assigned: Anonymous
Priority:
Type:
Opened on: Monday, October 29, 2007 - 13:47
Last modified: Monday, October 29, 2007 - 13:47

but they should look like this:

Case number: 100-11
Project: Helpdesk
Opened by: admin
Status: Open
Assigned: Anonymous
Priority: 1-High
Type: Bug
Opened on: Monday, October 29, 2007 - 13:53
Last modified: Monday, October 29, 2007 - 13:53