Sorry
Found the solution. Use
Domain Masquerading
Domain Masquerading
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