Recently Heard on Match

Sometimes I think maybe it's not so bad to be single. Below is a recent conversation with a guy via dating site IM, my comments are in brackets (Background info: he contacted me first after looking at my profile, where I should state I have plenty of pictures in addition to a description of myself)
Him: hi
Him: we were both online
Me: Works for me.
Me: [long pause...ok, I'll try to start the conversation] So when is your triathlon?
Him: on september if I am ready
Me: Nice. What distance are you doing?
Him: for now I run 8 miles and bike 30
Me: That's great.  I'm sure you'll be ready by Sept.
Him: you look very hot btw
Me: [ok, non-sequitur, but whatever] Thanks, but flattery will only get you so far. ;)
Him: what you mean?
Me: I enjoy a good conversation.  :)  [I'll try to ignore the fact that your IMing skills would imply that this is a stretch for you.]
Me: [Another long pause, time to make an exit and be polite] Oh, I just realized the time.  I should probably go.  But let me know if you want to grab a drink sometime....
Him: do you have big boobs? [Ummm, seriously!?? Did he really just type that?]
Me: Wow. You'll never know...

[Close window. Pour wine. Appreciate my solitude.]

To Email or Not to Email...

That is the question.  When someone writes to me and I am definitely not interested in the person (too old, different interests, not someone I'm attracted to, etc.) what do I do?  I understand it's hard to send an email to someone (I've had the twisted stomach anxious feeling myself when I press send) but is it better to be rejected kindly, too the point, or is it best to just ignore it completely? I guess I would prefer a nice email if it were me (even a lie about currently dating someone would be appreciated).  But in my head I'd like to say: 

Dear toosexy69,
Thanks, but no thanks. I'm just not sure we have anything to TALK about.

Dear Calling1973,
Although I really appreciate the courage it must have taken to send this email (assuming you didn't just send it to everyone that you found attractive, because really you said absolutely nothing that pertained to me in particular in the five lines you did send).  I'm just not sure that we would be a good match.  Good luck with your serial emailing, errr, I mean dating.

Dear joesmith2011,
Seriously you put amicable in your headline? Since you really don't say anything at all about yourself in your profile and you don't really include a very good picture, I think I will stay equally as bland with my response. Stay amicable.

Dear pappa65,
I think you should be ruled out specifically because you are the same age as my father. I realize you didn't actually send me an email but I noticed you checked out my profile - even though my age is listed quite clearly (Yes, I know you looked. Technology is amazing isn't it?).  I think I need to logout now. And just to make sure I'm clear this is not an email that suggests I'm interested, I'm not into the Hugh Hefner thing...  good luck with your search though.