Just if somebody else is searching for the same thing, although it is not directly related to XOA:
If you want to get these alerts by mail and you are not using XCP-ng-Center, you can activate them with:
xe pool-param-set uuid=pool-uuid other-config:mail-destination=mail@example.com
xe pool-param-set uuid=pool-uuid other-config:ssmtp-mailhub=mailserverip:port
KPS