Reference: https://www.regular-expressions.info/email.html
I took the last regular expression example that appears at the end of the above web page and made some improvements:
-
I replaced every
‘
character (left single quotation mark, code U+2018) with the correct`
character (grave accent/backquote/backtick, code U+0060). -
I replaced the last
{1,63}
with{2,63}
so that the top-level domain must be at least 2 characters long instead of 1.