untested and just making this up, but something like this should work:
| lookup host_email.csv
| search "error1" OR "error2" OR "error3" OR "error4" OR "exception1" OR "exception2" OR "exception3" | stats count values(_raw) by host
| search action.email=1 action.email.to=email_address
| map maxsearches=0 search="stats count
| fields - count
| sendemail email@example.com to=$action.email$ subject=$alert.subject$ message=$alert.message$ sendresults=true"
You might need to modify to work correct, and read about the sendemail command here https://docs.splunk.com/Documentation/Splunk/latest/SearchReference/Sendemail and the map command here https://docs.splunk.com/Documentation/Splunk/latest/SearchReference/Map
Hope this helps ...
... View more