CHAPTER 2 |
SIMS Key Features
|
Many businesses have realized that the ability to allocate their email services by outside vendors is cost and time effective to their businesses. Hosting a large number of email services for these organizations is then accomplished by service providers.
This chapter describes how the key features of the SunTM Internet Mail ServerTM enable service providers to deliver corporate outsourcing.
Topics in this chapter include:
|
|
Virtual hosting support |
|
|
Vertical and horizontal scalability support |
|
|
Delegated management capability |
|
|
Provisioning interfaces |
|
|
Monitoring tools |
Corporations demand that their Internet addresses look and feel as if they own their dedicated server, even when they are being hosted by an service provider (SP). Key to this concept is the Internet DNS namespace. For example, on the public Internet, email must be addressed to smith@stream.com and not to stream@bridge.net. Similarly, on the private Intranet, users connect their mail clients and browsers to stream.com and not some magic name inside bridge.net. Besides reinforcing the subscriber's own identity, this also separates them from changes in their SP.
Historically, SPs have approached this by dedicating their entire servers to each subscriber domain, which is too expensive for very small accounts. To address this need, SIMS enables the individual servers to support many domains, giving the impression that each domain has its own server. This capability is known as virtual hosting. In turn, the concept of the DNS domains hosted by such servers is known as hosted domains.
SIMS provides an automated process for creating and managing new virtual hosts in the LDAP directory, which creates appropriate rewriting rules in the IMTA.
See "Address Rewrite Rules" on page 60 in Chapter 7, "Internet Message Transfer Agent," for more information on rewrite rules.
See Chapter 6, "Domain Hosting with SIMS," for domain hosting components and specifications.
See "Virtual Hosting Scenario" on page 24 in Chapter 4, "Deployment Scenarios," for a case study of a virtual hosting scenario.
SIMS 4.0 supports populating a large number of users in the directory. The key criteria are search speed from the message access servers, the rate of addition of new entries, the rate of modification of existing entries, the time to synchronize the IMTA (incremental and full), and the time to synchronize LDAP Slave servers with the master. Achieving these goals require improved caching, smart installation tools, application specific tuning tools, and enhancements to the directory server itself.
To implement these requirements, SIMS provides both vertical and horizontal scalability models. Vertical scalability refers to maximizing the use of the available hardware, adding new resources to enable an existing server run proportionately faster. Horizontal scalability refers to the ability to connect multiple servers so that they act as a single logical server. The performance of the logical server can be increased by adding more physical servers.
See "Horizontal Scalability Scenario" on page 27 in Chapter 4, "Deployment Scenarios," for a case study of an horizontal scaleability scenario.
SIMS 4.0 Delegated Management capability enables an SP who provides email services to a customer to outsource the administration of that customer's mail domain to the customer. This ensures that customers can only perform a prescribed set of operations on a prescribed set of entries and attributes residing only in that part of the directory which corresponds to the customer's mail domain.
To perform these administration tasks, SIMS allows creating one or more delegated administrators for each hosted domain. A delegated administrator is able to create and edit users and distribution lists within the specific domains. A single level of delegation is provided; that is, the delegated administrator is unable to delegate sub domain managers. SIMS provides delegated management capability by using any Web browser. The GUI look and feel for the Delegated Management Console is customizeable.
SIMS provides provisioning interfaces to enable the SPs write applications for integrating their order entry, billing, and systems management software with the mail server.
SIMS also publishes the Directory and IMTA configuration interfaces to facilitate the migration tools between the Mail server and customer account databases, like Oracle or Sybase. This includes the ability to create, modify, and delete new virtual hosts.
See the Sun Internet Mail Server 4.0 Provisioning Guide for information on provisioning the SIMS LDAP directory with users, distribution lists, administrators, and domains by creating and importing LDIF records.
The common term anti-spamming refers to a broad set of services that protect the mail server and its user community from the undesirable effects of Unsolicited Commercial E-Mail (UCE), popularly referred to as spam. The first priority is to protect the server from denial of service attacks, which have become increasingly common. The second priority is to reduce the clutter in subscriber's mail folders, where UCE can cause lost messages due to exceeding quota limits.
SP sites deploy many tools to assist in site status monitoring, error recovery, tracking down security violations, billing customers for usage, and other administrative tasks. Many use commercial enterprise monitoring systems, where as others use entirely home grown tools. These tools require that the mail server provides published interfaces for monitoring server health, obtaining historical data (logs and audit trails), gathering statistics, and administering the system.
Two types of monitoring interfaces are provided:
|
|
Control and Monitoring--Internal control CLIs and dynamic monitoring parameters, supporting integration of systems management software (for example, Tivoli) with the mail server. |
|
|
Domain Logging and Statistics--Provide detailed per-domain logging and report generation capabilities, allowing writing applications to generate their own report formats and billing systems. |