As somebody who has been there before, it's 100% possible to use email for notifications and have that fully scriptable, but given how extremely stringent email providers have become over the decades and still getting tougher as we speak, i would very much recommend not depending on email for this. Ideally you'd have multiple channels in case one fails for the REALLY vital stuff, but at least you should have one that is not email. There's many:

• One of the various ways to generate push notifications that have been mentioned in the thread
• Chat messages, people have mentioned using Telegram, Signal or others, and some of those have desktop version too
• Yes, email, but not as the only way, you don't wanna stop receiving notifications because Google just decided your IP is spamming and is bouncing all your alerts
• One of the various cloud notification things like the AWS ones mentioned (pretty sure all the cloud providers have their own version)
• Something like a monitoring service or self-hosted server (I've used Zabbix in the past and like it, although this is FAR more involved)
• Text messages? This will depend on services on your area, here they're so rare i never consider this option
• Others i can't think about right now (need more coffee)

Whatever you do have in mind that ANY of these can fail, so if there's anything truly critical be sure to both have a way to know if one notification system is failing, and to have a plan B to receive notifications/alerts even if one is down. Depends on how critical stuff is of course, for tests you don't need triple redundancy or whatever, but for the service the company's income depends on you don't wanna have a system that stopped working and you never knew.