Sorry for delayed response. One way you could prevent users from deleting email is to block deleting of records in Access Groups setting. If this is not an option for you please let me know.
This is not the issue of upgrade SERP. But serverip.dat in this case contains the value: 192.168.88.12:1301, so this is local IP of the server with SERP.
Anyway I don't understand what do you me...
