Proof HQ is incorrectly flagging email addresses with an underline ("_") between first and last name as invalid. These are valid. I can not enter new users with email addresses using this configuration.
You are correct, an underscore is a valid character. I have tried this on our sign up, new contact and new proof pages and they all allowed the underscore.
Where in the application did you experience this problem?
ProofHQ is an online proofing system that streamlines the process of managing document reviews, proofing and approvals. Sending proofs with ProofHQ is as easy as using email, but with much better tracking and follow-up. ProofHQ reduces the time and cost of managing proofing and approvals for everyone involved. ProofHQ can be used by graphic designers, web designers, ad agencies, marketing departments, industrial designers, printers, pre-press companies, public relations, photographers and more.