server

type AllowAddrFunc func(addr string) bool

type Authenticator interface {
	Authenticate(username, password string) (AllowAddrFunc, error)
}

type Server struct {
	Hostname     string
	TLSconfig    *tls.Config
	Auth         Authenticator
	DeliverLocal deliverFunc
	AllowProxy   bool //All mail to be sent neither to a local address nor from
}