Someone

import Text.Regex
import Data.Maybe (fromJust)

mail :: Regex
mail = mkRegex "(([a-zA-Z0-9]+[ \t]+)?[a-zA-Z0-9]+[ \t]+)?((mailto://)?[a-zA-Z0-9]+@[a-zA-Z0-9]+(\\.[a-zA-Z0-9]+)+)"

mainmatch s = case m of {
        Nothing -> [];
        Just (pre, mm, post, sub) -> (sub!!0, sub!!2):mainmatch post
} where m = Text.Regex.matchRegexAll mail s

mama = mainmatch "asdfa sdf as           asdf@dgdsfg sdfg@sdfg sdgd ijhb@dfg   mailto://u_quark@hotmail.com Lefterhs Kritikos el010149@mail.ntua.gr afta kai alla polla me thn Olga Tremh olga@mega.tv"