MAIL
Because there is no direct connection between two non-adjacent domains, you cannot define the routing path between them in a Connection document. Connection documents can only be used between two directly-connected, adjacent domains. However, users in non-adjacent domains can send mail to each other by routing it through the intermediary domain.
One way to do this is to use explicit addressing -- telling the Router how to reach the destination domain through the intermediary domain by placing the entire routing path in the address field. For example, if Kathy Burke in domain A wants to send a message to Robin Rutherford in the non-adjacent domain C, she addresses the message by way of domain B, as follows:
Although the use of explicit addressing is an effective method for directing mail to non-adjacent domains, because it relies on a complete knowledge of the inter-domain routing topology, it's also not a very practical solution. This information is not readily available to a typical user. To simplify routing and addressing to non-adjacent domains, you can create a Non-adjacent domain document in the Domino Directory to define the path between the non-adjacent domains.
Using a Non-adjacent domain document
Administrators can create a Non-adjacent domain document to control message routing to a non-adjacent domain. A Non-adjacent Domain documents serves three functions:
But when a Non-adjacent domain document is available, the Router obtains intermediary domain information from that document. This eliminates the need for users sending mail to a non-adjacent domain to use complex, explicit addressing. Thus, if domain A has a Non-adjacent domain document for domain C, when Kathy Burke in domain A sends mail to Robin Rutherford in domain C, she uses the address Robin Rutherford@C (rather than Robin Rutherford@C@B). Because the Router finds the intermediate domain information in the Non-adjacent domain document, the message is transferred successfully to domain C by way of domain B.
Using Non-Adjacent domain documents to restrict mail
Using Non-adjacent domain documents to simplify addressing makes them valuable enough. But Non-adjacent domain documents play another equally significant role. Although they are not strictly required to enable routing between non-adjacent domains, they are needed if you want to restrict routing of messages from certain domains.
By default, any domains that can route mail to your domain can also route mail to the destination domains named in a Non-adjacent domain document. Mail routed from one domain to another through your domain consumes your network resources. To prevent your servers from being used to transfer mail between other domains, you can selectively allow and deny mail routing through your domain.
The Allow and Deny fields on the Restrictions tab of the Non-adjacent domain document let you control the flow of messages from other domains to the non-adjacent domain. Entries in these fields must be the names of adjacent domains; the Router ignores entries for non-adjacent domains beyond the previous hop. If you deny a domain from sending mail through your domain, the Router denies all mail received from that domain, including messages the domain may have passed on from another, non-adjacent domain.
The "Deny mail from domains field" in a Non-adjacent domain document does not block messages that use explicit domain addressing, that is, addresses that explicitly name every domain on the routing path. A Non-adjacent domain document can only block mail that relies on information in the Non-adjacent domain document to supply the name of a a missing intermediate domain. If the entire routing path is contained in the recipient address, the Router doesn't need to check the document to determine where to route the message, and thus cannot block it. For example, if in the previous example, the administrator in domain B creates a a Non-adjacent domain document for domain D and adds domain A to the Deny mail from domains field. Kathy Burke in domain A can still send mail to Judy Kaplan in domain D by specifying the following explicit domain address: Judy Kaplan@D@C@B.
To prevent Kathy Burke from sending this message, the administrator in Domain B would have to create an Adjacent domain document for domain C that names domain A in the Deny mail from domains field.
The settings in the Allow and Deny fields work in conjunction with the Allow and Deny fields on the Router/SMTP - Restrictions and Controls - Restrictions tab of the Configuration Settings document. In the event of any conflict between settings, Domino applies the most restrictive entry.
Messages may be further restricted by Adjacent Domain documents, Non-adjacent Domain documents, and Configuration Settings documents set up between domains along the routing path.
To create a Non-adjacent domain document 1. From the Domino Administrator, click the Configuration tab and then expand the Messaging section.
2. Choose Domains.
3. Click Add Domain to create a new Domain document.
4. On the Basics tab, complete these fields:
Also, the Domino Directory in the intermediary domain must have a Connection document to the destination domain.
Leave this field blank to allow any domain to route mail through the local domain to the non-adjacent domain.
Note Since, by definition, all servers in a domain use the same Domino Directory, only one Non-adjacent domain document is required for each non-adjacent domain. You do not have to create a separate document for each server.
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