Applies to: Exchange Server 2007 SP3, Exchange Server
2007 SP2, Exchange Server 2007 SP1, Exchange Server 2007
Topic Last Modified: 2006-09-08
Before you create an address rewrite entry that rewrites multiple domains, you must prepare your sub-domains. Also, before you perform any of the procedures that are described in How to Rewrite All E-Mail Messages from Sub-Domains, you must understand the requirements for rewriting e-mail addresses in multiple domains to a single domain, and the appropriate pre-configuration for the affected mailboxes and contacts.
When you flatten internal sub-domains into a single external domain, you must consider the following factors, which apply only when multiple sub-domains are being rewritten:
- Unique aliases are required All e-mail
aliases, the part of the e-mail address to the left of the @
symbol, must be unique across all sub-domains. For example, if
there is a firstname.lastname@example.org, there cannot be a
- Proxy addresses are required A proxy
address that matches the e-mail address that is produced by the
Address Rewriting agent must be configured on every e-mail account
that is in the sub-domains that are rewritten. For example, if
email@example.com is rewritten to firstname.lastname@example.org, the e-mail
address email@example.com must be added as a proxy address to Joe's
- Contacts may be required If you are
rewriting e-mail from a non-Exchange Server 2007 e-mail
system, you must create Active Directory mail-enabled contacts
for each e-mail address in the non-Exchange Server 2007
e-mail address that is being rewritten. This mail-enabled contact
must contain the original e-mail address and the rewritten e-mail
address. For example, if firstname.lastname@example.org is rewritten to
email@example.com, you must create a new mail-enabled contact in
Active Directory with firstname.lastname@example.org as the target SMTP
address and email@example.com as the proxy SMTP Address.
These factors are important because rewriting addresses in multiple sub-domains causes a many-to-one relationship between internal sub-domains and the externally visible domain. Because of this many-to-one relationship, the Address Rewriting agent cannot determine which sub-domain contains the correct recipient when a message that is addressed to the externally visible domain is received.
|Make sure that every e-mail alias that exists across all sub-domains is unique. Exchange Server 2007 does not check to verify that every e-mail alias that can be rewritten to a single domain is unique.|
Removing Conflicting E-Mail Addresses
To create an address rewrite entry that rewrites multiple sub-domains, you must first make sure that all e-mail aliases are unique across all your sub-domains. For example, consider the following configuration:
The following users are in the subdomains sales.contoso.com, marketing.contoso.com and research.contoso.com:
Each sub-domain has two users, and each user has a unique e-mail address. However, you want to rewrite the subdomains sales.contoso.com, marketing.contoso.com, and research.contoso.com into a single domain that is called contoso.com. Table 1 shows each original e-mail address and its corresponding rewritten e-mail address.
Table 1 Original e-mail addresses and corresponding rewritten e-mail addresses
|Original e-mail address||Rewritten e-mail address|
When the e-mail addresses in each sub-domain are rewritten, a conflict occurs between firstname.lastname@example.org and email@example.com, as indicated by the bold text in Table 1. Therefore, both e-mail addresses are rewritten to firstname.lastname@example.org. To resolve this situation, you must change the e-mail address of one of the recipient mailboxes to an address that does not conflict with the e-mail address in any other sub-domain.
Applying Proxy Addresses to Recipient Mailboxes
For internal recipient mailboxes to receive replies to addresses that have been rewritten, you must configure those recipient mailboxes by using a proxy address that matches the rewritten external address.
For example, if a mailbox exists for email@example.com, and the rewritten external address is firstname.lastname@example.org, the mailbox must be configured by using a proxy address that is set to email@example.com.