Direct mail to sellers who currently have agents

[Angel Hagen]

One of the target markets I am looking at for direct mail are those whose homes have been listed and not sold. I have identified zip codes in my area in which I would like to invest and I am narrowing down the housing currently listed in that area by how long it has been listed. 

I am thinking of starting direct mail to those whose homes have been listed either more than 6 months or more than 12 months (the areas I am targeting have median less than 30 days on the market). Is this acceptable since most of these properties currently will be listed by a realtor? My intent is not to circumvent the realtor or that relationship, but to provide the seller with an alternative option for a home that has not sold once that contract expires. 

Thanks for responding......