my customer do not want receive any more
undisclosed-recipients@zimbra.example.com
they would receive undisclosed-recipients

i searched wiki and i got this:
ManagingDomains - Zimbra :: Wiki
If you want mail from user@domain.com or user@zimbra.domain.com to appear to come from user@example.com, you can set the canonical address for the entire domain.
zmprov md domain.com zimbraMailCatchAllAddress @domain.com zimbraMailCatchAllCanonicalAddress @example.com
zmprov md zimbra.domain.com zimbraMailCatchAllAddress @zimbra.domain.com zimbraMailCatchAllCanonicalAddress @example.com

this doesnot convince me; i think that correct parameters to change are:
#myorigin = $mydomain
and
/opt/zimbra/postfix/conf ]# grep myorigin *
main.cf.default:append_at_myorigin = yes
main.cf.default:myorigin = $myhostname

any advice would be very apreciated
TIA