Cisco Cisco Email Security Appliance X1070 Troubleshooting Guide
What happens to incoming messages in the event
of a system failure on an ESA?
of a system failure on an ESA?
Document ID: 118015
Jul 18, 2014
Contents
Contributed by Dominic Yip and Enrico Werner, Cisco TAC Engineers.
Question:
What happens to incoming messages in the event of a system failure on an ESA?
If your ESA fails to respond due to loss of connectivity or system failure, your inbound emails will receive a
soft bounce (400−level SMTP error) and the sending MTA (Message Transfer Agent) will retry sending
emails based on its bounce profile.
soft bounce (400−level SMTP error) and the sending MTA (Message Transfer Agent) will retry sending
emails based on its bounce profile.
If you configured a secondary MX record, the retry will be directed to the host specified in the secondary MX
record. The SMTP standard suggest to try to retry for 4 days, most MTAs follow this guideline so even a
longer connection problem should not result in a lose of emails.
record. The SMTP standard suggest to try to retry for 4 days, most MTAs follow this guideline so even a
longer connection problem should not result in a lose of emails.
Updated: Jul 18, 2014
Document ID: 118015