Hello Jeroen,
You can follow the excellet article + video made by the MVP Ricardo Pereira on this subject:
Once understood the configuration in localhost, you can get the proper email server configuration with your IT department in order to deploy your app to production.
Hi Jeroen,
Although the blog of Ricardo is informative, it uses a fake SMTP server, I suspect you want to send out real e-mails.
The challenge of sending (forgotten password) e-mails is that you need an e-mail provider with server (accepting SMTP connections). Mendix doesn't provide this, so you need to use your own. It may be a Outlook/Hotmail/Gmail account, whatever, but you need those credentials to fill in at this step.
Hopefully this was the information you were looking for!
Regards,
Johan