10000 lines might not be enough. I'm not sure that it's possible to determine whether something is a valid email address other than trying to send mail to it. I

10000 lines might not be enough. I'm not sure that it's possible to determine whether something is a valid email address other than trying to send mail to it. If you haven't read the RFCs, they're pretty much a nightmare. The HTML5 spec has this little gem: > This requirement is a willful violation of RFC 5322, which defines a syntax for e-mail addresses that is simultaneously too strict (before the "@" character), too vague (after the "@" character), and too lax (allowing comments, whitespace characters, and quoted strings in manners unfamiliar to most users) to be of practical use here.[0] [0] https://www.w3.org/TR/html5/forms.html#e-mail-state-(type=email) https://www.w3.org/TR/html5/forms.html#e-mail-state-(type=em...