I had my cable ISP call me a couple times about a business account a few times. I run my own mail server. A POP3/SMTP account got hacked and started sending out spam. They're very polite, professional, ask you to fix the problem and move on.

I'm surprised you got a phone call, when I worked at a tier 2, we would just disconnect you and wait for you to call us instead.

running your own mail server is an exercise in pain. not sure if you're brave or dumb, but props to giving it a go.

Heh. I've been running my own since the mid 90's. Originally I worked for some early ISPs, and continued it as a hobby of sorts. (My main personal email is on gmail.)

If you're running an email server that is running at full throughput to send spam (due to your clear negligence) from a residential ISP account then depending on what plan you've purchased it may violate your terms of service.

I know of friends who have been banned for doing exactly this.

But you will get banned from your isp if they find out you are self-hosting a blog and photo album shared with family and friends.

Depends on your ISP. I use one of the biggest ones in the US, and they won't do any such thing. They don't care if you're running servers at all, unless you start getting a lot of incoming traffic -- then they'll ask you to upgrade to a commercial account or stop it.

I've been running servers used by family and friends from my home for about 20 years now. It's never been an issue at all.