How can we recontact a customer who write us before?

The client contacted us before to confirm if the apartment was occupied and it was, but now it is likely that the apartment may be available for the dates that he requested and that is why we want to contact him again. From the page we have not achieved it and for that reason we consult them, so that they explain to us the way in which we can do it? Garcias to all in advance and regards, Dilaida