9. A digital rights management method implemented in a rights management server computer, comprising: (a) storing a rights management policy table which contains a plurality of rights management policies, each rights management policy having a name and indicating one or more users and document access rights granted or denied to each user; (b) storing an attention-rights rule which defines a correspondence between attention types of email recipients and document access rights to be granted or denied for each attention type, the attention types including at least “to” and “cc;” (c) receiving, from a client computer or a scanner, a request which specifies a list of one or more users as recipients of an email and an attention type of each recipient, the request further including that a document is to be attached in the email; (d) determining, based on the attention type of each recipient and by applying the attention-rights rule, document access rights to be granted or denied to each recipient of the email; (e) determining whether the document access rights to be granted or denied to each recipient, as determined in step (d), match a rights management policy stored in the rights management policy table; (f) if a matching rights management policy is found in step (e), selecting the matching rights management policy; (g) if a matching rights management policy is not found in step (e), creating a new rights management policy based on the document access rights to be granted or denied to each recipient of the email determined in step (d), and storing the created rights management policy in the rights management policy table; (h) generating a unique document ID, associating the document ID with the rights management policy selected in step (f) or created in step (g), and storing the document ID; and (i) transmitting an encryption key and the document ID to the client computer or the scanner for encrypting the document to be attached in the email.
9. A digital rights management method implemented in a rights management server computer, comprising: (a) storing a rights management policy table which contains a plurality of rights management policies, each rights management policy having a name and indicating one or more users and document access rights granted or denied to each user; (b) storing an attention-rights rule which defines a correspondence between attention types of email recipients and document access rights to be granted or denied for each attention type, the attention types including at least “to” and “cc;” (c) receiving, from a client computer or a scanner, a request which specifies a list of one or more users as recipients of an email and an attention type of each recipient, the request further including that a document is to be attached in the email; (d) determining, based on the attention type of each recipient and by applying the attention-rights rule, document access rights to be granted or denied to each recipient of the email; (e) determining whether the document access rights to be granted or denied to each recipient, as determined in step (d), match a rights management policy stored in the rights management policy table; (f) if a matching rights management policy is found in step (e), selecting the matching rights management policy; (g) if a matching rights management policy is not found in step (e), creating a new rights management policy based on the document access rights to be granted or denied to each recipient of the email determined in step (d), and storing the created rights management policy in the rights management policy table; (h) generating a unique document ID, associating the document ID with the rights management policy selected in step (f) or created in step (g), and storing the document ID; and (i) transmitting an encryption key and the document ID to the client computer or the scanner for encrypting the document to be attached in the email. 16. The method of claim 9 , wherein step (i) further includes transmitting a name of the rights management policy selected in step (f) or the created in step (g) to the client computer or the scanner.