Regex Validate Email Address

This is a long and complicated process to make a 100% accurate regular expression to validate email address, but, I have a good one with 2 bugs, it reports the following valid email addresses as invalid:

user@domain.museum (6 letter domain which is only museum?!)

user@1domain.com (domain cannot start with numbers!)

Since I am not familiar with regular expressions I want to know if anyone knows how to fix this 2 bugs? Please explain each of them separately so in case I don't want to use the 1st fix I can!

Dim AddressPattern As String = _

"^(([\w-]+\.)+[\w-]+|([a-zA-Z]{1}|[\w-]{2,}))@" & _

"((([0-1]?[0-9]{1,2}|25[0-5]|2[0-4][0-9])\.([0-1]?" & _

"[0-9]{1,2}|25[0-5]|2[0-4][0-9])\." & _

"([0-1]?[0-9]{1,2}|25[0-5]|2[0-4][0-9])\.([0-1]?" & _

"[0-9]{1,2}|25[0-5]|2[0-4][0-9])){1}|" & _

"([a-zA-Z]+[\w-]+\.)+[a-zA-Z]{2,4})$"