McAfee MAP-3300-SWG - Web Security Appliance 3300, Product Manual

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Postmaster address
McAfee recommends that you assign a postmaster, so that queries from your users are handled
promptly. The postmaster must be someone who reads email regularly. You can use the name of a
single user or a distribution list.
Table 76 Option definitions
Option Definition
Postmaster address Specifies an email address that the appliance uses to deliver email that has a
recipient of postmaster.
We recommend that you specify an email address here, so that any delivery
problems are handled promptly. You can specify a distribution list or a single user
who reads email regularly.
DKIM signing
The Domain Keys Identified Mail (DKIM) technique uses RSA private and public keys and DNS TXT
records to enable the recipient to verify the identity of an email sender.
The sender signs the email message with a private key, by adding an extra header - the
DKIM-Signature header. The header provides the email message with a cryptographic signature. The
signature is typically derived from the message body and email headers such as From and Subject,
then encrypted by the sender's private key.
Recipients can verify that the message is genuine by making a query on the signer's domain to
retrieve the signer's public key from a DNS TXT record. The recipient then verifies that the email and
its signature match. The recipient can therefore be confident that the email was sent from the stated
sender and was not altered during transit.
The appliance can verify signatures from incoming mail and attach signatures to outgoing mail.
For information about Domain Keys Identified Mail (DKIM), visit the Internet Engineering Task Force
website,
http://www.ietf.org and http://www.dkim.org .
Use this section to create a Domain Keys Identified Mail (DKIM) key.
Table 77 Option definitions
Option Definition
Enable DKIM
signing
When selected, adds a DKIM header (like a digital signature) to each email message
as it is sent.
You must add a key before you can enable DKIM signing.
Domain name
and
Selector
During verification, the recipient extracts your Domain Name and Selector from the
signature to retrieve the public key associated with the appliance’s private signing key.
For example, if your Selector is mail and your Domain Name is example.com, the
recipient must issue a DNS query for the TXT record of mail._domainkey.example.com.
Signing key
Select the key to be used to sign the messages.
DKIM signing
keys
Allows you to create signing keys from numerous parameters.
Export
When clicked, allows you to save the private key to a file, in case the original private
key is lost or erased.
View Public Key
Place the public key on your DNS server or give it to your Internet Service Provider, so
that recipients can verify email from your organization.
Overview of Email features
Email Configuration
McAfee Email and Web Security Appliances 5.6.0 Product Guide 99