Gerrit-stage is currently sending out a vast number of emails because we automated closing old reviews without activity. Gerrit stage should not send out any emails. Additional note: This means, we can't this feature on in production without actually closing all the old reviews manually. We should perhaps get our bot to close about 100 reviews a day until we're caught up and then unleash the Gerrit configuration.
Current hacky fix: Michael stopped postfix and edited the main.cf file so anisble cannot turn it on.
I edited the Gerrit stage config to not send out emails.