Logged on as a user with domain admin rights, I try to add an alias to a distribution list list@mydomain.com, but i get this Zimbra error:

Error: permission denied
Message: permission denied:
need right: addDistributionListAlias for dl list@mydomain.com
Error code: service.PERM_DENIED
Method: AddDistributionListAliasRequest
Details:soap:Sender

This worked fine with the same user in 5.0.16 and stopped working after the upgrade. Any idea why?