I'm getting a 403 forbidden error inside one of my new client's network when they try to go to their own website. The website is hosted outside the network. I can't ping the site inside the network either. Every other website seems to work from inside the network. If I'm outside the network the website works fine and I can ping it as well. One of our 5 servers has IIS on it, but there is no website.
I think it may have to do with the ASA 5505 Cisco router. We had an expert come in and upgrade the license from 10 users to 50 users. We noticed this error about a week later, but we don't go to the website that often, so it may be a coincidence. Also, some of our users are no longer getting email (pop3) inside the network from other co-workers. The email is hosted outside the network as well.
Another possibility is the client's external IP was on 2 blacklists even though they don't have Exchange e-mail server on-site. But I did get them removed from these blacklists today.
Not sure where to start looking, open to suggestions.