/
^(?=^[\w.@!#$%&'*+/=?^`{|}~-]{7,254}$)(?<username>(?=^[\w.!#$%&'*+/=?^`{|}~-]{1,64}@)[\w!#$%&'*+/=?^`{|}~-]+(?:\.[\w!#$%&'*+/=?^`{|}~-]+)*)@(?<domain>(?=\b[a-z\d.-]{5,252}$)(?:[a-z\d](?:[a-z\d-]{0,61}[a-z\d])\.)+(?:(?:[a-z](?:[a-z-]{0,61}[a-z]))|(?:(?=[a-z\d-]*?[a-z])(?=[a-z\d-]*?[\d])[a-z\d](?:[a-z\d-]{0,61}[a-z\d]))))$
/
gi