How i can remove pdf-attachment from sign request email

I want to remove a pdf attachment from the email, where the customer is asked to sign the adobe sign-document by following the web link. The email customer gets also has the pdf file copy as an attachment, I want to remove it from the customer email. How can this be done?

At the moment when i send sign request to customer, customer usually wont click "sign here"-link and instead opens that pdf attachment copy of the document where is no sign request fields etc and process wont go right. If i can remove that pdf-attachment, all customers will click "sign here"-weblink and all is then nicely. Please help me a bit.

Thank you a lot!