Posting new nodes?

I have two email addresses set up in mailhandler new@domain.com and reply@domain.com. Once I started using mail2web I could nolonger post new messages to new@domain.com because "They must be sent in reply to a valid notification email." Now if I select On for "Passthru to mailhandler module" I can post new messages to new@domain.com but I can also post new messages to reply@domain.com.

Is there any way that only new@domain.com accepts new nodes and only reply@domain.com accepts new comments.

Thank you.