From email taken from form

Dear Developer,
I really love this plugin and I have created very different forms with it. Currently I am using just a simple contact form but I have a problem: I am using a ticketing system to organize incoming emails. For every new email address it creates automatically a new user.
To do this I need the sender’s mail address as the from email field. I have seen that it is possible to use the email form field to populate the from email field in the settings. The name before the @ is correct but unfortunately I receive my own domain ending afterwards.
Is there any solution for this problem?
Thanks in advance and best regards,
Meike