|I think you may be getting a little confused here because I certainly am.|
You don't send Email via a scanner. Emails are digital and sent over a network with an email address like MyName@hotmail.com
Fax is an analogue system that sends data point to point over the analogue telephone system and all you need for that is a telephone number,
If you are wanting to send an enclosure with an Email the way to do it is to scan it into a document then send it with the Email as an attachment. Fax doesn't come into it.
If you are wanting to send a letter by fax which includes that enclosure then I assume you are trying to send them all together via the fax machine, In this case Email doesn't come into it.
The error "Occupied" is not one I am familiar with but suggests that the telephone line you are using to send the fax is already in use which, if you are trying to use dial-up Internet to send an Email at the same time would be the case,
Can you give more details to exactly what you are trying to do.