Sooner or later email blacklists become the nightmare of most system administrators. Long story short - when your email provider is reported as a source of email spam, a lot of your email messages won't reach your family, friends, business partners, loyal and prospective customers alike.
Becoming part of a blacklist isn't what gets other email providers to filter you, it is the way they decide to do so. Blacklisting causes problems when the administrator decides to simply filter out all emails coming from a network device on a blacklist. Medieval doctors did a similar job when taking off an arm to save the patient from an infected finger. Clean email has no chance of reaching its intended location. Decent e-mail service providers usually filter spam, employing methods that utilize multiple filters before deciding whether an email message is spam or not.
Email blacklists can be IP-based and domain-based. There are a lot of blacklists out there. A week-to-week comparison of DNS blacklists is available on sdsc.edu. If your e-mail gets filtered as spam, it is very likely it has become a part of one or more of the blacklists provided on that site. Actually, if you want to filter some spam e-mails you might consider using one of the suggested blacklists.
How can you get out of a blacklists, or get the good e-mail accounts unblocked? You can try contacting the blacklist provider and promise them you will track down the spammer and never have the same problem again. That is impossible. Not the part where you track the spam account, but the part when this never happens again. No one can guarantee that. In many cases it is beyond the administrator, for one reason or another. It is way more efficient to contact the administrator of the server which is not receiving you messages and deal with them. If that does not work, try contacting the party not receiving your email and get them to speak with the administrator. That might be even better and it is more likely you sort out the situation faster.
Is your server or domain blacklisted? Find out here.