Part of your zmmtactl status run returned:
+ /opt/zimbra/bin/postfix status
+ '[' 1 -ne 0 ']'
Which tells me it thinks postfix isn't running - but, if you see it, and can telnet to port 25, and get the banner, means that something's wrong with this script.
So - sh -x /opt/zimbra/bin/postfix status may tell us more - can you post the output from this?