White Label!

Hi!
I have a question concerning WordPress.
I have a webshop and an Affiliate Program. When users register for Afilliate Programs or buy products they atutomatically get a message with WordPress Tittle instead of my Company Name as well as the e-mail adress wordpress@mysite.com.
How can I fix this issue. My clients get confused about this. I need to have my own e-mail and title as the mail sender for mye customers.
Thanks,
Arturo.