Question from UK about Direct Mail

[Piotr Damek]

Hello. 

I was trying to search the forum but couldn't find an answer to my question.

I live in UK and I purchased my 1st property few months ago and now I am thinking of buying another one. 

I listen to BP podcast and I see that Direct Mail is being mentioned here quite often. 

I would like to know: how do you find lists of house repossessions, mortgage arrears, etc ?

I know that here in UK, there are companies that sell these lists but how do I know whether the company selling it is legit? 

Are there any questions you recommend I should ask  before I purchase the list?