In Exchange 2019, like other versions like 2016 or 2013, you can delete a mailbox using a single command. To firstly find the list of mailboxes you can run the following command:

  • Get-Mailbox

In this example we are going to remove the mailbox called "edward". To remove it you can use the following command:

  • Remove-Mailbox edward

You will be prompted to confirm removal. If you don't want to be prompted you can use the following command:

  • Remove-Mailbox edward -Confirm:$all