Pre-installation FAQ for Symantec Email Submission Client (SESC)

Article:TECH175916  |  Created: 2011-12-01  |  Updated: 2013-10-24  |  Article URL
Article Type
Technical Solution


This document contains information that you need to know before you install Symantec Email Submission Client.


Question:  Does Symantec Email Submission Client (SESC) support a mixed-mode Exchange environment?

Answer: No. In a mixed-mode environment, you must install separate instances of SESC for each version of Exchange.

For example, in a mixed-mode Exchange environment that has Exchange 2007 and Exchange 2010 installed in the same environment, you must install separate SESC instances for each Exchange version.


Question:  Can I install Symantec Email Submission Client on an Exchange server?

Answer: Technically, there is no known issue; you can install SESC on an Exchange server. However, Symantec recommends that you install SESC on a separate server or virtual machine for better maintainability of both Exchange server and SESC.


Question:  How many mailboxes does a single instance of SESC support?

Currently there is no known upper limit on the number of mailboxes handled by deploying SESC on a single computer.  Depending on the hardware, software and networking environment more computers with SESC deployed may be desirable.

Symantec has done internal testing with a single computer with SESC handling a domain with thirty-thousand (30,000) mailboxes.  The results are here:

Initial mailbox creation time ~4 hours
Subsequent daily mailbox monitoring ~1 hour
Additional peak CPU load on Exchange Client Access Server 10-15%
Additional peak memory load on Exchange Client Access Server 30-40MB
Additional peak memory load on Exchange Mailbox Server 20-30MB
Additional peak CPU load on Exchange Mailbox Server 5-8%
Processing 1000 email submissions a day No additional load








Question:  Are there any recommendations or suggestions for SESC deployment best practices?

Answer:  While creating and monitoring the folders, the System Update job runs based on the number of mailboxes and adds some load on the CAS. Symantec recommends that you schedule this System Update job during off-peak hours. For Exchange 2010, if you have one CAS managing more than 5,000 mailboxes, Symantec recommends that you create a new throttling policy with the following parameters set to “NULL” and associate the policy with the SESC service account.  The default throttling policy allows for a maximum of 5,000 subscriptions.

Use the following article to create a custom throttling policy that allows for greater limits:  How to set the throttling policy for Exchange 2010 for use with Symantec Email Submission Client (SESC).

Question:  What is the best practice to install and configure SESC on an Exchange multisite environment?

Answer:  Assuming the sites are linked by a reliable network and appropriate bandwidth, then you should install SESC in one Active Directory (AD) site and add the Exchange servers from the other AD site.  If the sites do not have good network bandwidth and speed, we recommend that you deploy SESC to each AD side to avoid any network latency which could cause delays while submitting the messages.


Question:  How are subscriptions managed by CAS servers in a multi-site environment?

Answer:  Each CAS server maintains subscriptions for mailboxes from its own site. When there are multiple sites and mailbox servers are managed across different sites, each CAS maintains subscriptions for mailboxes from its own site. The Exchange CAS creates subscriptions by sending a proxy request from one CAS to other CAS server depending on the site location of the mailboxes.


Question:  What happens when the configured CAS server is down and how to recover from it?

Answer:  In a multi-site environment, if one of the CAS servers is down, the subscriptions for the mailboxes are lost from that site only. Once the CAS is recovered, the subscriptions may be recreated by selecting the mailbox servers from that site on the SESC User Interface and by running the System Update with the “Perform force subscription” option. If the CAS server to which the SESC is pointing is down, you can configure the CAS URL from a different site and continue to use SESC.

Question:  What are the pre-installation requirements for Symantec Email Submission Client?


  • Ensure that the system requirements are satisfied.

  • Ensure that you log on as Windows domain administrator on the computer where you install Email Submission Client.

  • Ensure that the computer on which you install Email Submission Client communicates with the domain controller.

  • Ensure that the Basic Authentication and Windows Authentication in the Internet Information Service (IIS) security components are enabled.

For more information, see Symantec Email Submission Client Implementation Guide.

Article URL

Terms of use for this information are found in Legal Notices