Regarding the opensmtpd test failure:THis is completely unrelated to the privileging problem (we invoke the unprivilegded one which results in a warning but we dont really use it and only check if mail gets delivered)
THe problem is that we check /var/spool/mail for the mail but opensmtpd seems to deliver to /var/mail instead.
From the buid log of opensmtpd: checking system mail directory... /var/mail from _PATH_MAILDIR
