Not able to switch to secondary Mail Server when the primary mail server is down.

Not able to switch to secondary Mail Server when the primary mail server is down.

Hi I've configured my secondary mail server to function as backup server. So that when the primary mail server is down, secondary mail server will take over. However, it doesn't work. Got this message when the primary server is down.
 
"The action Email address has failed because the email address associated in the E-Mail Action is wrong/not present. The action email adress has failed because the email address asscociated in the E-Mail Action is wrong/not present.com.sun.mail.smtp.SMTPSendFailedException: [EOF]"
 
I am using AppManager10
 
Can advise me pls.

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