HOW TO set up the required IAM permissions for WorkMail??

Hi! If you're trying to reset a user password for WorkMail, go to the workmail console (https://console.aws.amazon.com/workmail/), then go to organizations, then users, then select the user and reset their password.

If you're looking for managing WorkMail via an IAM User or Role, you can manage credentials via the IAM Console or API: https://docs.aws.amazon.com/IAM/latest/UserGuide/id_credentials_access-keys.html