@sultansofswing you can modify DB directly use it at your own risk:
select objectid from objectproperty where propname=‘emailaddress’ and value=‘user@example.com’;
gets you objectid:
±---------+
| objectid |
±---------+
| 1025 |
±---------+
update objectproperty set value=1 where objectid=1025 and propname=‘ishidden’;
then do “kopano-admin --sync”