I need to do a link witch can start a process model. How I can do this?

For this to work the user receiving the email would have to have a valid Appian user account. But then you could just assign a task to him. By default he would receive an email including a task link he could click on.
As I understand the use case this is about a person without an account who will not be able to directly take any action in Appian. As I said, integration via email reply is easy.

For this to work the user receiving the email would have to have a valid Appian user account. But then you could just assign a task to him. By default he would receive an email including a task link he could click on.
As I understand the use case this is about a person without an account who will not be able to directly take any action in Appian. As I said, integration via email reply is easy.