Help! mail not working after failed update to Plesk Obsidian

Hi all,

I was upgrading the last of our Linux servers to Plesk Obsidian.
All the other upgrades went smoothly but the upgrade here crashed out.
The box is running CentOS 6.

The mail service no longer works.

if I check the mail server logs I see -

dovecot_authdb_plesk[4584]: No such user 'email@dalau.com' in mail authorization database

When I go to view mailbox configuration within the Plesk GUI for any domain I see the following error -

Type Smb_Exception...

Help! mail not working after failed update to Plesk Obsidian