Direct Mail - Tips to avoid mailing same ppl on different lists??

[Joey Zaniboni]

Hey everyone, I am working on a few different direct mail campaigns and am wondering if anyone has any tips or systems they use to make sure they are not mailing the same people on more than one campaign? I know overlap will be inevitable if we are mailing multiple lists. For example we are doing a vacant property list and a tax default list, and it's reasonable to assume that a seller might fall under both of those categories. As our number of mailings increases, I want to make sure we are efficiently weeding out the duplicates, especially if the number of duplicates could be significant.

Any tips would be much appreciated!