Me again.
Thanks to
Bug 33720 – Add zimbraAliasTargetId of real domain to alias domain and allow auth with alias domain addresses I found the correct "full" zmprov command:
Code:
[zimbra@zimbra ~]$ zmprov cd domain.fr zimbraDomainType alias zimbraDomainAliasTargetId domain.com zimbraMailCatchAllAddress @domain.fr zimbraMailCatchAllForwardingAddress @domain.com
51fc62b3-d089-4e3b-b4d7-96d16b7bf4e4
[zimbra@zimbra ~]$