OK, let’s say I have a domain, example.com (no, that’s not my domain…I’m using it as an example!). I get an internet connection at home, via DSL or cable, from an ISP that has a good spam policy and stays out of blacklists. I set up email so that mail to whate…@example.com goes to one of the POP boxes my ISP provides. I use my ISP’s SMTP server for outgoing mail. Since my ISP has a good spam policy, all is well.
Now, suppose I decide that the web space or services that come with my DSL is not good enough (to small, no database access, etc), and I don’t want to have www.example.com point to my home machine, because my home machine is not reliable enough (no UPS, flakey power in winter, etc). So, the obvious solution is to find a hosting company, and stick www.example.com there. Email for the domain stays with my ISP and my home machine. Just the web stuff goes to the hosting company.
Question: suppose I pick a hosting company, and they turn out to not be as careful as one would like when it comes to keeping out spammers, and end up getting blacklisted. What effect does that have on web sites hosted there? It is possible to use SPEWS or other IP based blacklists in firewall configurations – ie. deny all traffic from that IP, or to just drop connections to web server ports, but I don’t know of anyone who is actually doing this.