Replying to For Sale adverts

[Angus7]

I was sent an auto-generated email from the car sales section from someone who is interested in a car I have for sale. It included an email address for a reply. Unfortunately when I tried to reply I got a 'mail undeliverable' message from their email server.

How do I get in touch with someone who has a duff email address, presumably picked up from their profile ?

Thanks
Angus