Yellow, I get emails all the time and never really think of them as a suckup, because they are usually seeking information.
Of course there's a clumsiness factor, but some of my best students did weird contortions - I remember one boy who came in to the room for interview and announced he'd read all my books - and he had, too. Suckup? Yes, but ambitious, too, and he got the top Distinction in Mods, and a top first later. I wouldn't recommend it, but I wouldn't dismiss much more flagrant stuff than a shy email. Note to all - of course we didn't take him because of this! Just saying it didn't rule him out.
I prefer to hear from candidates and not from schools or parents. To me it's no different to attending an open day. If they want to know something, why not ask?