Zimbra Email "Rate-Limiting" to Fight Phishing

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Zimbra Email "Rate-Limiting" to Fight Phishing

Postby jimm » Tue Nov 13, 2012 8:19 pm

On Thursday, November 15, Technology Services will implement additional steps to limit the impact of phishing attacks on faculty and staff using the Zimbra email system. We will activate an additional capability of our Ironport spam filters that will prevent Zimbra users from sending email to more than 500 recipients per hour. For most users, this will have no impact unless they fall victim to a phishing attack. Very few of us ever have the need to send so many emails in one hour but phishers will send may more than this number of messages from an account they have gained access to through phishing attacks.

The new "rate-limit" filter will automatically prevent any more email messages being sent from an account once email has been sent to more than 500 recipients in any one-hour period. This should limit the ability of phishers to use compromised Fresno State accounts to send spam and phishing emails. In addition, this will make it much less likely that our mail system will be "black listed" by other email providers like AOL, Yahoo, Hotmail and Gmail; interfering with our email correspondence with users of these services.

If you do not send email to more than 500 recipients per hour from your Zimbra account, there is no action you need to take. If you do have a need to send email to more than 500 recipients per hour using Zimbra, please contact our Help Desk at 559.278.7000 or submit a work order via the web through our on-line system at help.fresnostate.edu/forms/ In the unlikely event that you receive an email message indicating that our Ironport system has rate limited your Zimbra email account please contact the Help Desk for assistance.

Please be aware that this new "rate-limit" filter will not affect your use of Listserv lists, Fresno State Messaging or Blackboard to send email messages. These services will continue to allow you to send email to more than 500 recipients per hour. If you have any questions regarding this change to our email service, please contact our Help Desk or email me at jimm@csufresno.edu.

Thank you,

Jim Michael - Executive Director, Technology Services
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Joined: Wed Jun 27, 2012 9:44 am

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