You appear to mean "directly before the @". Thanks for the clarification. Email::Valid::Loose further clarifies:
Email::Valid::Loose is a subclass of Email::Valid, which allows . (dot) before @ (at-mark). It is invalid in RFC822, but is commonly used in some of mobile phone addresses in Japan (like docomo.ne.jp or jp-t.ne.jp).
So the items identified so far:
- Allow /\.\@/
- Disallow /\@.*%/ (actually more, since you answered my question in the negative in a private /msg and promised more details later)
- Disallow CFWS w/in the address
- Require /\@.*\./
- Require /\.[a-zA-Z]{2,}$/
- Require RFC1035-compliant domain (except empty ones)
- Extend RFC1035 to allow domain labels that start with a digit
- Disallow quoting (usually of $local_part)
- Disallow escaping (usually of $local_part)
- Disallow /\+.*\@/
- Disallow "group"s (/$display_name:$mailbox_list;/)
- Disallow "name-addr" (/$display_name?$angle_addr/)
- Disallow "obs*" (obs-angle-addr, obs-mbox-list, obs-addr-list, obs-local-part, obs-domain)