need help with start-stop-daemon to run chrooted program.

[seriv]

Hi All!
I need help, I do not understand details of start-stop-daemon program handling. I want use it to run XMail mail server in chrooted jail from regular user xmail.
I prepared this chrooted jail, copied all setup, executable and library files. When I run this with '-Md' parameter, which is similar to '-d' in sshd, preventing forks and detaching from console, it works fine. The only problem was to bind to privileged ports, I was to switch to unprivileged and use iptable packet redirection to immitate binding on pop3 and smtp ports.
===
start-stop-daemon --start -c xmail -r /chroot/xmail \
--startas /var/MailRoot/bin/XMail --pidfile=/var/run/XMail.pid --\
-Pp 29110 -Sp 29025 -Fp 29079 -Md
===
it works fine, I've checked it's SMTP and POP3 sessions. But if I remove '-Md' parameter from XMail's commandline to fire it as a daemon, it returns immediately without any error message.
Can anybody help?

Thank you,
Sergey.

[seriv]

1) the problem was in /dev/null, I forgot to create it in chroot.
2) the tool to find it is strace. with option -f to trace forked processes.
3) the result as a ebuild for great XMail mail daemon is published at http://www.spectr.org/sergey/XMail_for_Gentoo.html
Sergey