Email alerts not working after coordinator upgrade (4370109)

Coordinator server was upgraded to latest version, then after the upgrade all the enabled alerts are not sending email. Errors similar to the following may be logged in the Coordinator log:

[ERROR][ChangeAuditor.Coordinator.ReportProcessorTask.SendEmail(0)] Could not send Microsoft Mail message, Unrecognized mail service.

And the following logged with debug logging enabled:

[DEBUG][ChangeAuditor.Coordinator.AlertProcessorEmailTask.OnStart(0)] No mail service specified for Email alerts