IronPort - advanced configuration guide

Routing: Alias Expansion
Sample Routing Queries
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Cisco IronPort AsyncOS 7.6 for Email Advanced Configuration Guide
Chapter 3 LDAP Queries
AsyncOS supports alias expansion (LDAP routing with multiple target addresses). AsyncOS replaces the
original email message with a new, separate message for each alias target (for example,
recipient@yoursite.com might be replaced with new separate messages to newrecipient1@hotmail.com
and recipient2@internal.yourcompany.com, etc.). Routing queries are sometimes known as aliasing
queries on other mail processing systems.
Table 3-3 Example LDAP Query Strings for Common LDAP Implementations: Routing
Query for: Route to another mailhost
OpenLDAP (mailLocalAddress={a})
Microsoft Active Directory Address Book May not be applicable
Microsoft Exchange
a
SunONE Directory Server (mail={a})
(mailForwardingAddress={a})
(mailEquivalentAddress={a})
(mailRoutingAddress={a})
(otherMailbox={a})
(rfc822Mailbox={a})
a.Active Directory implementations can have multiple entries for the proxyAddresses attribute, but
because AD formats this attribute value as smtp:user@domain.com, that data cannot be used for LDAP
routing/alias expansion. Each target address must be in a separate attribute:value pair. Microsoft
Exchange environments that are aware of each other within the infrastructure can usually route mail
between each other without involving a route back to the originating MTA.
Routing: MAILHOST and MAILROUTINGADDRESS
Masquerading
For Routing queries, the value of MAILHOST cannot be an IP address; it must be a resolvable hostname.
This usually requires the use of an Internal DNSconfig.
MAILHOST is optional for the routing query. MAILROUTINGADDRESS is mandatory if MAILHOST
is not set.
Masquerading is a feature that rewrites the Envelope Sender (also known as the sender, or MAIL FROM)
and the To:, From:, and/or CC: headers on email based on queries you construct. A typical example
implementation of this feature is “Virtual Domains,” which allows you to host multiple domains from a
single site. Another typical implementation is “hiding” your network infrastructure by “stripping” the
subdomains from strings in email headers.
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