EAI doesn't really specify anything "more" than the older SMTP about validating email addresses. Everything in the local part >= U+0080 is permissible and up to the server to sort out what characters it wants to allow, how it wants to map things like Turkish I, etc. Some code points are clearly really unhelpful in an email local part, but the EAI RFCs leave it up to the servers how they want to assign mailboxes.
Obviously you could check the domain name to make sure it's a valid domain name, and the ASCII range of the local part to make sure it respects the earlier RFCs, and the lengths, but you won't really know if it's a legal name until the mail does/doesn't get accepted by the server. AFAIK there isn't a published regex for doing the limited validation that is possible. -Shawn From: [email protected] [mailto:[email protected]] On Behalf Of James Lin Sent: Wednesday, October 30, 2013 1:42 PM To: [email protected]; [email protected] Subject: Re: Best practice of using regex on identify none-ASCII email address Let me include the unicode alias as well for wider audience since this topic came up few times in the past. From: James Lin <[email protected]<mailto:[email protected]>> Date: Wednesday, October 30, 2013 at 1:11 PM To: "[email protected]<mailto:[email protected]>" <[email protected]<mailto:[email protected]>> Subject: Best practice of using regex on identify none-ASCII email address Hi does anyone has the best practice or guideline on how to validate none-ASCII email address by using regular expression? I looked through RFC6531, CLDR repository and nothing has a solid example on how to validate none-ASCII email address. thanks everyone. -James
