Release 8.0.5.GA.5839.UBUNTU12.64 UBUNTU12_64 FOSS edition. (i believe originally created at 8.0.4)

i use zmlocalconfig -e postfix_always_bcc=archive@archive.css1.net to set this value, and it shows up there:

zimbra@zcss:~$ zmlocalconfig | grep always_bcc
postfix_always_bcc = archive@archive.css1.net

but on a reboot, zmlocalconfig still shows it as set, but:
postconf | grep always_bcc

shows it as NOT set (and indeed, emails are not being forwarded)!? any suggestions!? i've got another server with basically the same configuration and its working fine (so i know in general it works). the only difference i can see/think of is the working one was built originally as a v6.?.? (then upgraded through 7 and now 8)

thanks!