Since Postfix 3.5.9 dropped Berkley DB support, the map type hash is deprecated and lmdb is the suggested default map type but Webmin does not support it.
This map cannot be edited : Webmin does not support the map type lmdb
Therefor i cannot add/remove/edit anything concerning mail accounts in neither Webmin nor Virtualmin.
Please add lmdb support to the Postfix module or suggest another map type which doesn't use Berkley DB.
Thank you in advance
Thanks for pointing this out - it will be fixed in the next release of Webmin.