On Thu, Sep 05, 2019 at 03:45:47PM +0800, Wesley Peng wrote: > Is there the username specification for email system?
It is called "local-part". And yes, RFC 5321 and 5322 have a pretty comprehensive spec for it. The following is a valid e-mail address for example: "<script>alert('Ohhai')</script>"@43-1.org Regards, Bastian -- It is undignified for a woman to play servant to a man who is not hers. -- Spock, "Amok Time", stardate 3372.7