Using the FPE capacity planning tool
The Forefront Protection 2010 for Exchange Server (FPE) capacity planning tool can be accessed at the following URL: https://go.microsoft.com/fwlink/?LinkId=191021
This tool can help you understand the system requirements necessary to support your desired Exchange deployment with FPE. You should read through the directions and readme portions of the tool before starting.
One important note about spam in this tool: for the Edge Transport servers, you will see an incoming SMTP message rate. If spam filtering is not enabled, this message rate represents the incoming messages into your organization that are delivered to the end user, filtered, or detected as containing malware. If spam filtering is enabled, then the SMTP rate reflects the filtered messages, the malware detected messages, the delivered end-user messages, and the messages that have been detected as spam at the content filter level. Different organizations characterize SMTP rates differently; the SMTP rates included in the tool are full SMTP messages that have the ability to be quarantined in their entirety. The other SMTP traffic composed of spam includes the connections rejected and the ultimate messages being discarded due to IP reputation or sender type filtering. This includes most of the spam detected in the system and varies based on the size of the organization; therefore, the percentage used is outlined in the tool as 90.16% total spam detections.
As an example:
# of Mailboxes: 20,000
User Load Profile: 300 messages/day
Keyword/File Filtering: Moderate
SMTP Message Rate without Spam Enabled: 39.48 Messages/Sec
Actual Message Rate into Hub: 39.17 Messages/Sec
SMTP Message Rate with Spam Enabled: 46.84 Messages/Sec
Connection rejected per second: 39.48 connections rejected/sec
Spam Content Filter Detection Rate: 7.36 Messages/Sec
Spam Pre-Content Filter Filtering Rate: 351.23 Messages/Sec
Total SMTP Activity: 398.07 Messages/Sec
The intent of the tool is to provide you with enough information to understand your hardware needs based on the configuration of your Exchange environment. The typical hardware used to generate this data is outlined in the tool and you should evaluate your hardware needs based on the information provided via the links in the tool for relative system comparisons.