That's an interesting choice of rules. When cutting down the complexity so drastically, do you really need to double the length of your regex just to enforce the rule that dashes only appear in the middle of a domain segment? This version is so much more legible:

  /^[a-zA-Z0-9.!#$%&'*+\/=?^_`{|}~-]+@[a-zA-Z0-9-]{1,63}(?:\.[a-zA-Z0-9-]{1,63})*$/

Hostnames starting or ending with dashes tend to work in the real world anyway.