Email alerts

I want to automate a process which allows me to send an email alert (for the first time)to the customer when the server is ready (Server dedicati Economici | Low-cost servers | OVHcloud).
Then I need to think a flag if I will have already send the email before or not and if not will send the email (if is available to buy).

If anyone knows something regarding this or anyone has related links please share.
Thanks in advance

maybe you can to the owner of the application if there are any triggers already done in there.
then you dont need to automate anything