Okay, after looking at your Contact page on your website, I see that you already put your email addy there for harvesters anyway, so it won't matter then that your form has it.
In that case, try putting this in your html form:
<input type="hidden" name="email" value="email@example.com">
Make sure, however, that you change the field name that the Submitter uses to enter their email, because you can't be using the same "email" one. You might change theirs to "E-Mail". The script uses "email" (all lower case) for the "From:", so you will be safe to use any other variation of the word for the Submitter's input email area.