How to go about changing email passwords based on them being setup with this tutorial?

https://library.linode.com/email/postfi ... -addresses

INSERT INTO `mailserver`.`virtual_users`
  (`domain_id`, `password` , `email`)
VALUES
  ('5', ENCRYPT('newpassword', CONCAT('$6$', SUBSTRING(SHA(RAND()), -16))) , 'email3@newdomain.com');

Maybe like this:

UPDATE `mailserver`.`virtual_users`
SET password=ENCRYPT('newpassword2', CONCAT('$6$', SUBSTRING(SHA(RAND()), -16)))
WHERE email='email3@newdomain.com';

I ran this on one email and was able to then login via roundcube to test it. Figured it worked, so I ran it on three other emails. Now I can't access any of them via roundcube or email clients like mailbird/outlook. I think I broke something.

Mail log is showing "Warning: mysql: Query failed, retrying: MySQL server has gone away", "warning: dict_nis_init: NIS domain name not set - NIS lookups disabled".

Not sure how editing the email account passwords would make mysql issue. The password used for the account lookups wasn't changed.

I can connect via mysql workbench using mailserver user and see all the email accounts and aliases fine.

Rebooted and back in business. I think I was banned from fail2ban and the connection attempts.