The disk where my Zimbra Open Source Edition is installed got corrupted.
After I corrected the errors with fdisk, the whole /opt/zimbra/postfix/libexec was missing. I copied it from another running Zimbra to see if it would restore the "postfix/postqueue fatal: Queue report unavailable" but it didn't.

Now I have a non-functioning mail server where the MTA doesn't start.

Is there any procedure to restore my install without losing accounts/passwords/configuration and emails ?

Many thanks for your help