JSI Tip 7448. The Windows XP Fax Service reports that 'Some recipients were discarded because their addresses don't appear to be fax numbers'?

When you send a fax to a contact in the Windows Address Book, you receive:

Some recipients were discarded because their addresses don't appear to be fax numbers.
(IDS_BAD_ADDRESS_TYPE)

If you sent the fax to a contact, and to a group that contains that contact, you will experience this behavior.

To prevent this error, don't send a fax to duplicate contacts.