How do you handle the awkward phone call when....

[Jeremy S.]

your direct mail letter is sent to a seller who has their property listed with an agent? 

I forgot to add the "please disregard this letter if your property is listed with an agent" to my latest round of mail.  The first question I ask is, if the property is listed and if it is, I just say I will check it out online and set up an appointment with their agent if I am interested.

But it's so awkward!! Most of them assume you mailed to them BECAUSE their property is listed.  I had a guy call me and just start talking about how he was getting feedback about potential buyers not liking the wallpaper but they painted the room blue now and I would love it... I asked if the property is listed and acted like I was an idiot and said "of course its listed"

I'm sure these people are left feeling very confused, there has got to be better way to handle these calls, any suggestions?  I am an agent myself and do not want to discuss any details with another agent's client. Anyone know a way to check your mailing list against the mls to avoid even spending the money to mail these people?