I have noticed that Address.String() and ParseAddress() functions don't match RFC 5322, especially regarding quoted-strings, and some other special cases.

Most simple way to find out if Address.String() and ParseAddress() do their job, is to look if a parsed and formatted mail address can be parsed again, which isn't the case: https://play.golang.org/p/Kl0FDI-BxO

package main

import "fmt"
import "net/mail"

func main() {
    a, _ := mail.ParseAddress(`" "@test.com`)
    fmt.Println(`" "@test.com`)
    fmt.Println(a)
    _, err := mail.ParseAddress(a.String())
    fmt.Println(err)

    fmt.Println()

    a, _ = mail.ParseAddress(`"hello@world"@test.com`)
    fmt.Println(`"hello@world"@test.com`)
    fmt.Println(a)
    _, err = mail.ParseAddress(a.String())
    fmt.Println(err)

}

" "@test.com
< @test.com>
mail: invalid string

"hello@world"@test.com
<hello@world@test.com>
mail: unclosed angle-addr

I fixed this problem, and wrote tests for other special cases: https://go-review.googlesource.com/#/c/8724/
I created this patch request a month ago, but hadn't got any answer unfortunately...