Harvesting and distributing a certificate based on a DNS name

1. A method for use in a delivery manager, the method comprising:

Receiving, at a delivery manager, from a first sending system of a plurality of sending systems, a certificate that a Domain Name Service (DNS) associates with a DNS name of a recipient system;

distributing the certificate to the plurality of sending systems in response to the delivery manager receiving the certificate, each sending system configured to:

store the certificate in a local memory of the sending system;

in response to a future determination to send an encrypted message to the recipient system, use the certificate from the local memory of the sending system to perform encryption; and

send the encrypted message directly to the recipient system; and

the first sending system configured to:

obtain the certificate from the DNS in real-time when sending a message to the recipient system for which the first sending system does not have the certificate; and

provide the certificate to the delivery manager for distribution to the other sending systems.

2. A system, comprising:

a delivery manager and a plurality of sending systems, the delivery manager comprising:

an interface configured to receive, from a first sending system of the plurality of sending systems, a certificate that a Domain Name Service (DNS) associates with a DNS name of a recipient system; and

processing circuitry configured to distribute the certificate to the plurality of sending systems in response to the delivery manager receiving a new or updated certificate;

wherein each sending system is configured to:

store the certificate in a local memory of the sending system;

in response to a future determination to send an encrypted message to the recipient system, use the certificate from the local memory of the sending system to perform encryption; and

send the encrypted message directly to the recipient system; and

the first sending system configured to:

obtain the certificate from the DNS in real-time when sending a message to the recipient system for which the first sending system does not have the certificate; and

provide the certificate to the delivery manager for distribution to the other sending systems.

3. The system of claim 2 , wherein the DNS name of the recipient system corresponds to an individual mail client.

4. The system of claim 2 , wherein the DNS name of the recipient system corresponds to a mail transfer agent.

5. The system of claim 2 , the processing circuitry further configured to:

send a request message from the delivery manager to the DNS, wherein the request message requests the certificate associated with the DNS name of the recipient system; and

wherein the interface receives the certificate as a result of the processing circuitry sending the request message.

6. The system of claim 5 , wherein the request message is sent according to DNS-based Authentication of Named Entities (DANE) protocol.

7. The system of claim 5 , wherein the processing circuitry is further configured to initiate a discovery procedure such that the request message is sent to the DNS without requiring the recipient system to inform the delivery manager that the certificate exists.

8. The system of claim 5 , wherein the processing circuitry is configured to send the request message in response to a determination that the sending system failed to send the encrypted message directly to the recipient system.

9. The system of claim 8 , wherein the determination that the sending system failed to send the encrypted message directly to the recipient system is made based on data reported from the sending system.

10. The system of claim 2 , the processing circuitry further configured to notify the recipient system in response to the delivery manager determining that there is a problem with the certificate received from the DNS.

11. The system of claim 2 , the processing circuitry further configured to:

send an invitation message to the recipient system, wherein the invitation message invites the recipient system to become a member of the plurality of sender systems.

12. The system of claim 11 , wherein the delivery manager further comprises a certificate repository comprising other certificates associated with other recipient systems, and wherein, in response to the recipient system becoming a member of the plurality of sender systems, the processing circuitry is further configured to distribute the other certificates to the recipient system.

13. The system of claim 2 , the processing circuitry further configured to:

receive a current certificate that the DNS associates with the DNS name of the recipient system;

determine that the current certificate differs from the previous certificate; and

distribute the current certificate to the plurality of sending systems.

14. The system of claim 13 , wherein the processing circuitry is further configured to periodically send request messages to the DNS, wherein the request messages request the current certificate associated with the DNS name of the recipient system, and the current certificate is obtained as a result of periodically sending the request messages to the DNS.

15. The system of claim 2 , wherein the processing circuitry is configured to distribute the certificate to the plurality of sending systems according to regular intervals.

16. The system of claim 2 , wherein the certificate comprises one or more of: a key identifier, a public key, information about a version, and a signature.

17. The system of claim 2 , wherein the processing circuitry is configured to make the certificate available to the plurality of sending systems concurrently without having to wait until a time when each respective sending system begins processing that requires the certificate.

18. The system of claim 2 , wherein the processing circuitry is configured to use distributed file version management technology to distribute the certificate to the sending systems.

19. A non-transitory computer readable medium storing logic that, when executed by processing circuitry of a delivery manager, is operable to cause the delivery manager to perform actions comprising:

receiving, at a delivery manager, from a first sending system of a plurality of sending systems, a certificate that a Domain Name Service (DNS) associates with a DNS name of a recipient system;

distributing the certificate to the plurality of sending systems in response to the delivery manager receiving the certificate, each sending system configured to:

store the certificate in a local memory of the sending system;

in response to a future determination to send an encrypted message to the recipient system, use the certificate from the local memory of the sending system to perform encryption; and

send the encrypted message directly to the recipient system; and

wherein, the first sending system is configured to:

obtain the certificate from the DNS in real-time when sending a message to the recipient system for which the first sending system does not have the certificate; and

provide the certificate to the delivery manager for distribution to the other sending systems.