Ever since I keep my personal mail server at a certain DC, it here and there gets listed with Microsoft with a message “Blocked due to user complaints or other evidence of spamming” at their Smart Network Data Service (SNDS), even though I strictly use it for personal, transactional emails (that means 5-20 emails sent/received a day, and even though I can account for each email sent. Furthermore, when I think of it, I wasn’t even sending towards their SMTP or exchange services at all.
This has happened so many times, that I have to publish an article about it.

So, it could be that someone else is spamming at the data centre I’m in with the server, that has some IP that is “close” to mine.Naturally, the DC denies all of this, and says it’s my own problem.

That said, what’s left to do?

First, you can monitor your IP or IPs at the SNDS that I have mentioned before, which you can reach at this link. You’ll need some MSN account for this.
You can  register your IP(s) with them at the Access control option, and create something popularily called a FBL loop, that will let you know if you get any complaints for the IPs you registered (I dind’t get any…).

And finally, if you see it blacklisted, you can make a plead with them to delist your IP on this link.