E-mail firewall

• US 20070214353A1
• Filed: 12/19/2006
• Published: 09/13/2007
• Est. Priority Date: 07/24/1997
• Status: Active Grant

• Current Assignee: Axway Incorporated (Axway Software SA)
• Original Assignee: Tumbleweed Communications Corporation (Axway Software SA)
• Inventors: Dickinson, Robert, Krishnamurthy, Sathvik
• Granted Patent: US 7,380,274 B2
• Time in Patent Office: Days
• US Class Current: 713/154
• CPC Class Codes: H04L 2209/76 Proxy, i.e. using intermediary entity to perform cryptographic operations network architectures or network communication protocols using hop-by-hop encryption H04L63/0464
• CPC Class Codes: H04L 51/063 Content adaptation, e.g. replacement of unsuitable content
• CPC Class Codes: H04L 51/212 using filtering or selective blocking
• CPC Class Codes: H04L 51/224 providing notification on incoming messages, e.g. pushed notifications of received messages
• CPC Class Codes: H04L 63/0227 Filtering policies mail message filtering H04L51/212
• CPC Class Codes: H04L 63/0245 Filtering by information in the payload
• CPC Class Codes: H04L 63/0263 Rule management
• CPC Class Codes: H04L 63/0428 wherein the data content is protected, e.g. by encrypting or encapsulating the payload
• CPC Class Codes: H04L 63/0464 using hop-by-hop encryption, i.e. wherein an intermediate entity decrypts the information and re-encrypts it before forwarding it

Abstract

An e-mail firewall (105) applies policies to e-mail messages (204) between a first site and a plurality of second sites in accordance with a plurality of administrator selectable policies (216). The firewall comprises a simple mail transfer protocol (SMTP) relay (202) for causing the e-mail messages (204) to be transmitted between the first site and selected ones of the second sites. A plurality of policy managers (216) enforce-administrator selectable policies. The policies, such as encryption and decryption policies, comprise at least a first source/destination policy (218), at least a first content policy (202) and at least a first virus policy (224). The policies are characterized by a plurality of administrator selectable criteria (310), a plurality of administrator selectable exceptions (312) to the criteria and a plurality of administrator selectable actions (314, 316, 322) associated with the criteria and exceptions. The policy managers comprise an access manager (218) for restricting transmission of e-mail messages (204) between the first site and the second sites in accordance with the source/destination policy (218). The policy managers (216) further comprise a content manager (220) for restricting transmission of e-mail messages (204) between the first site and the second sites in accordance with the content policy (220), and a virus manager (224) for restriction transmission of e-mail messages (204) between the first site and the second sites in accordance with the virus policy (224).

Claims

1. An e-mail firewall method for restricting transmission of e-mail messages between a first site and a plurality of second sites in accordance with a plurality of administrator selectable policies, said firewall comprising:

utilizing a simple mail transfer protocol (SMTP) relay for causing said e-mail messages to be transmitted between said first site and selected ones of said second sites;

applying a plurality of policy managers, responsive to said SMTP relay, for enforcing administrator selectable policies, said policies comprising at least a first source/destination policy, at least a first content policy and at least a first virus policy, said policies characterized by a plurality of administrator selectable criteria, a plurality of administrator selectable exceptions to said criteria and exceptions, said policy managers comprising, an access manager for restricting transmission of e-mail messages between said first site and said second sites in accordance with said source/destination policy;

applying a content manager for restricting transmission of e-mail messages between said first site and said second sites in accordance with said content policy; and

applying a virus manager for restriction transmission of e-mail messages between said first site and said second sites in accordance with said virus policy, each of said e-mail messages including at least one recipient address, the e-mail control system transmitting a message to said at least one recipient address in response to a predetermined policy result of a policy manager.

2. The e-mail firewall method as set forth in claim 1 wherein said policy managers further comprise a format manager, responsive to said administrator selectable policies, for converting said e-mail messages from a first format to a second format.

3. The e-mail firewall method as set forth in claim 1 wherein said e-mail messages are formatted into a plurality of fields comprising a source field, a destination field, subject field, and a message field and wherein said access manager is responsive to said source/destination policy specified for each of said fields of said e-mail messages.

4. The e-mail firewall method as set forth in claim 3 wherein said e-mail messages are further characterized by a size field and wherein said access manager is responsive to said source/destination policy specified for said size field.

5. The e-mail firewall method as set forth in claim 3 wherein said e-mail messages are further characterized by a date and time field and wherein said access manager is responsive to said source/destination policy specified for said date and time field.

6. The e-mail firewall method as set forth in claim 1 wherein said virus manager is responsive to e-mail messages containing compressed information for detecting viruses contained in said compressed information.

7. The e-mail firewall method as set forth in claim 3 wherein said content manager is responsive, in accordance with said content policy, to information contained in said subject field and in said message field.

8. The e-mail firewall method as set forth in claim 7 wherein said e-mail message further comprises an attachment field and wherein said content manager is responsive, in accordance with said content policy, to an attachment designated in said attachment field.