For some very good reason you might would like to 
setup a 'autoreply' only account, without storing the incoming mail into a mailbox. If not already done, create an account via Delegated Admin Gui or commadmin Commandline Tool. 
   
  Example: 
   
  /opt/sun/comms/da/bin/commadmin user create -D admin -d vmdomain.tld -w enigma -F Mike -l  
    mparis -L Paris -W tester -E 
[email protected] -S mail -H mars.vmdomain.tld 
   
   
  
Setup mailDeliveryOption to autoreply mode only, so no email will be stored in the user mailbox, skip this step if you want incoming emails stored in the mailbox. 
   
  ldapmodify -D "cn=Directory Manager" -w enigma -f /tmp/modfile 
   
  [/tmp/modfile] 
  dn: uid=mparis,ou=People,o=vmdomain.tld,o=red 
  changetype: modify 
  replace: mailDeliveryOption 
  mailDeliveryOption: autoreply 
   
   
  
Setup mailSieveRuleSource with the autoreply text and 'do-not-reply' From address. The "Thank you ..." part becomes the subject. The next string in quotes is the body part of the message. The ":hours 0" denotes that we want a reply sent for every message. Finally,  the \n is used because of the wanted newlines in the body. 
   
  ldapmodify -D "cn=Directory Manager" -w enigma -f /tmp/addfile 
   
  [/tmp/addfile] 
  dn: uid=mparis,ou=People,o=vmdomain.tld,o=red 
  changetype: modify 
  add: mailSieveRuleSource 
  mailSieveRuleSource: require "vacation"; vacation :hours 0 :reply :from "do-not-reply 
    @domain.com" :subject "Thank you for contacting webpost" "Your Mail is being review 
    ed.\nTo access contact information please visit : http://www.domain.com \nPlease do  
    not reply to this e-mail as it is an automated response on your mail being accessed 
    .\n\nPublic Respose Unit.\n"