Use another table for user lookup

Hello,
I have in my MariaDB database used table users for other needs. Is
there any opiniion to use another table such as emails which has
structure

CREATE TABLE `emails` (
  `id` int(5) NOT NULL auto_increment,
  `email` varchar(255) NOT NULL,
  `password` mediumtext NOT NULL,
  `user_id` int(5) NOT NULL,
  `domain` varchar(255) NOT NULL,
  `enabled` int(1) NOT NULL,
  `virtual` int(1) NOT NULL
PRIMARY KEY (`id`))

so email address is concatencated from `email`@`domain`

I use this docs - https://www.ijs.si/software/amavisd/README.sql-mysql.txt

Thanks in advance,
Filip Bartmann