RE: Create a Note ans use @mention: Email Notification
Hi,
You can do a plugin create message on the Post entity.
Check if the @ sign exists in the post, and you can get the user info from it.
In general when you see a @name in the post the action text behind it is:
@[8,SystemUserId,"SystemUserName"]
If you want to create it, you can use the following line of code:
String.Format("@[{0},{1},\"{2}\"]", "8", systemUserId, systemUserName);
The 8 stands for the entity type code, while the other two variables are the entity Id and name.
Once you get the User Id of the person that is mentioned in the post, you can generate an email to be sent to the user.
Regarding the second question, I don't think there is a supported way to do this.
Hope this helps.