You add a free user only once, the letter will come to him in two cases:
you did not add it in the "Settings" - "Users" section, but wrote to him in the transaction in the chat. (it will automatically appear in the "Settings -" Users "section in the free users section.) He will send an email to the specified mail with the text of your message.
You added it through the "Settings" - "Users" section, through the "Free Users" button and an email will be sent to you that it has been added to your account.