Email Validation - Give up now?

/[a-z\-\.]+@[a-z\-\.]+/i

As many of you know, currently there are some stupidly lengthy regular expressions out there to validate whether an email address is actually valid before you send an email to it.

I'm posting to tell you to sod all validation of emails beyond something like that above...

My reasoning? With the impending regulation that allows businesses to register any extension that they want - there will be no way to track every possible extension or anything like that - as many Regular Expressions do at the moment.

Some people I know will be disregarding email validation completely when the new extensions are released. What are your thoughts, are you going to do this, or carry on trying to tackle every extension?

Regular Expression might not be 100% valid