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Understanding system requirements
Factors that affect performance
Environmental factors that affect performance
Historical usage patterns of your particular deployment will affect system
performance. Prior to installation, collect information about your environment
to understand typical usage patterns:
■
Outgoing SMTP connections –
This can cause additional overhead by
swelling disk queues with email destined for remote email servers which
may not be immediately accepting new email. Larger queues on disk result
in reduced MTA performance. Ideally, inbound and outbound mail streams
should be configured to work on separate machines.
■
Microsoft Indexing Service
– If you are running Windows, stopping or
disabling Microsoft Indexing Service can improve disk I/O time and boost
performance. See your Microsoft Windows documentation for more
information.
■
External MTA performance –
If appropriate, determine the performance of
the MTA sending incoming email to your MTA, and the performance of your
gateway MTAs and message store.
The characteristics of messages sent and received can impact performance. Key
parameters to identify are:
■
Median message size
■
Average number of messages per day
■
Number of messages with attachments
■
Average attachment size
■
Types of attachments
■
Percentage of virus-infected messages in the email traffic
■
Types of end-users (ISP or enterprise)
Settings that affect performance
The choices you make when configuring Symantec Mail Security for SMTP
affect its performance.
Filtering performance considerations
Multiple group policies
– If a message has more than one recipient, each with
different group policies, then the Scanner may need to bifurcate the message
(split it into one or more messages) for modification prior to delivery. Bifurcated
messages resulting from many group policies may degrade performance. Use
