network database notes

Types of messaging systems
1. shared file
a. central server used to store messages
b. client software does most of the work
c. Microsoft mail, Unix mail servers by ISPs are shared file
d. Don’t do any active processing
e. Post office structure was simply a shared folder stored on a network server

Disadvantages
a. Email sent to multiple recipients is copied to each recip. mailbox
b. Doesn’t scale well
2. Database messaging (also known as client server)
a. Uses a central DB to store messages for all users
b. Client software doesn’t access the db directly
c. All emails are stored and retrieved from the db by a service running on the email server, which actively processes each message
d. Exchange, lotusNotes, Novel Group Wise
e. Very scalable
f. More efficient – messages sent to >1 user are stored only once and a pointer to the message is sent to all recipients


Exchange 2003 features
AD integration - since exchange 2000 – exchange uses AD as its directory service – no longer maintains its own DB
Cluster Capable – compatible w/ windows clustering - allows exchange to be installed on multiple servers but only running on one at a time.
Policy-based management -
1. recipient policies
a. can define criteria for groups of users – different naming convention for certain groups
2. server policies – manage groups of servers – set mailbox limit
Recipient management flexibility – can have several types of recipients
1. user – most common
2. distribution groups
3. security groups
4. contacts
5. public folder

Exchange client software – can be a server for several email clients
- outlook – many of the ADV features of exchange are only available with outlook
- OWA - outlook web access – great for mobile users
- Internet clients – outlook express , Eudora
- Protocols – smtp, pop3 and imap4
Public Folders - used to store shared calendars, discussion groups
Scalability - supports ‘scaling out’ (clustering)
- Multiple exchange servers can be organized into routing group
Security – can delegate admin tasks to parts of EXC – spread workload and prevent one person from controlling an entire Exchange organization
- supports s/mime – secure MIME – allows you to encrypt internet email
- OWA can be encrypted w/ ssc
- 3rd software available for antivirus / spam

Disaster recovery - new version of “NT BACKUP” ships w/ exchange 2003
- allows you to backup exchange databases while users are still using it (only backs up entire DBS)
- 3rd party software can back up and restore individual email
Upgrade – exchange 5.5 to 2003