XADM: Sending Encrypted Mail to Users with Different Encryption Levels (181921)
The information in this article applies to:
- Microsoft Exchange Server 4.0
- Microsoft Exchange Server 5.0
- Microsoft Exchange Server 5.5
This article was previously published under Q181921 SUMMARY
Using the Microsoft Exchange Key Management Server, users have the ability
to encrypt messages. The North American version of the Exchange client can
encrypt messages using a 64-bit encryption key. This level of encryption
cannot be exported out of the United States and Canada; therefore,
international Exchange clients are only enabled with 40-bit encryption.
This article describes what happens when a user with 64-bit encryption
tries to send a messages to other users, some of whom have 64-bit
encryption and others have 40-bit encryption.
MORE INFORMATION
The level of encryption that a mailbox is enabled with is stored in the
Exchange directory. When you send a message to a user, it is possible
to determine what level of encryption that user has.
When a user with 64-bit encryption sends an encrypted message to a
mixed group of users with 40-bit encryption and 64-bit encryption, Exchange
uses the strongest encryption level that all recipients have in
common. In this case, it selects 40-bit encryption. A 64-bit client can
read a message encrypted with a 40-bit key.
If any one of the recipients is not security-enabled, then the Exchange
client displays a message asking the sender either to send the message
without encryption or to remove the users who are not security-enabled from
the list of recipients.
| Modification Type: | Minor | Last Reviewed: | 4/28/2005 |
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| Keywords: | kbinfo kbusage KB181921 |
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