^[^\.][a-zA-Z0-9!#$%&'*+\-\/=?^_`{|}~\.\"\(\),:;<>@\[\\\]]+@(([^\-][\w\d\-\.]{1,63}\.){1,}\w{1,63}|[^\-][\w\d\-\.]{1,63}|((25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)|([a-f0-9:]+:+)+[a-f0-9]+)$
Matches:
[email protected]
[email protected]
uwu@somelocalhostname
[email protected]
ip6@2001:db8:3333:4444:5555:6666:7777:8888
Doesn't match:
john@::ffff:0.0.0.0