Orchestrator mail alerts is like sending error summay report for every 10mins in case of any error events. It is a kind of monitoring for every 10mins and if there is no error on that 10min timebox, no mails would be sent. A mail will be triggered only if there is some error event happened in the 10min timebox.
There wont be any instant email alert after an error event. Hope this helps.
Follow the steps for setting up a password for your gmail, https://docs.uipath.com/orchestrator/docs/setting-up-email-alerts
Kindly check your orchestrator mail settings as below
SMTP Username - your email ID
SMTP Password - the password you generated from the above link
Test email once, to make sure settings are right.
Save it. You will receive alert summary report for every 10mins only if there is any error.
Alert mails which I recieved,