I have installed nBill and everything works great.
At this time I will be using it for manual invoicing and when an invoice is ready I would like to send it by email.
Tried with no success and this error:
The failure reason was not reported by the CMS. Check that you are using valid e-mail addresses (from and to) and that your server is capable of sending e-mails.
But I checked Joomla configs and everything works fine (also with Acymailing for newsletters which, in fact, send emails correctly)
Thank you so much