I'm trying to built a custom code that should run on Subscription event. As we know, When people Subscribe to a Sp List, you receive a Mail Message on your Box. I Should intercept that Event.
I've been searching for a While but I've only found ListItem Envets like this SPEventReceiverType Enumeration
or
this AlertTypes
Creating an alert/creating a subscription doesn't fire the same kind of event like creating or updating an item. As you correctly looked up, there is no such event and from my understanding you can't modify the confirmation email which is being send out.
You could only (and I don't recommend doing that) NewSub.aspx page which is used for creating new alerts via UI to not send out regular confirmation mails and send custom emails instead, although sending emails from js is the next challenging part here.
