How to allow local device like printer to send mails using smtp and basic authentification (clear password) via exchange 2007 server?

How to allow local device like printer to send mails using smtp and basic authentification (clear password) via exchange 2007 server?

I would like to allow devices like printers to send mails (notifications) using smtp and basic authentification (clear password) via exchange 2007 server?
The devices is on the same network as the Exchange server. And I would like create a specific windows account for each devices, to be used for authentification.
The current Exchange server have two send connectors one for the * address space (internet), a second one for the domain address space (*.domain.com):

get-sendconnector :

Identity               AddressSpaces                      Enabled
--------                      -------------                                 -------
domain.com         {SMTP:*.domain.com;1}      True
Internet                 {SMTP:*;1}                              True


I've to create an other sender connector?

And what about the receive connector for the device allowed to send smtp mails?
I must have basic authentification checked, in the authentification tab. Other paramaters?
And in the "permission groups" tab:
Which options must be selected among:
Anonymous users
Exchange users
Exchange servers
Legacy Exchange Servers
Partners

And what about the permissions (Add-adpermission commands)?
Wich permissions:
ms-Exch-SMTP-Accept-Any-Recipient
ms-Exch-SMTP-Submit
ms-Exch-SMT-Accept-Any-Sender
Others?

Thank you.

Jm