@winnniemaster I had a look at one of the form plugins we’re using and I think it can be quite a simple task with the following setup (tried briefly with Gravity Forms, but I think Ninja and others also allow this):
– One email field for the target address (I don’t think you want to disclose all existing users to your service providers)
– One email field for the source address (so the recipient knows who to contact in case of questions, and can hit “reply-to”)
– One File Upload Field (set maximum filesize to something that actually fits into the average inbox, <10mb)
All of them set to “required”
Next, you create a notification message, where you set the “TO:” field to the target address, the “FROM:” field to the Source Address, and check “Attach uploaded files to notification”so that the uploaded file is sent to the target.
If you plae this form on a page where only registered users have access, you should have no problem with spam. But you could add a recaptcha integration, just in case.