why is my email blacklisted?

There are two ways your email address can be considered spam and as a result, get blacklisted. The first is if you are abusing the email address. If you are spending spam and lots of junk to people through automated software, email exchanges will see your email address as spam. Your email will be added to blacklists to prevent all of this automated spam to prevent the junk mail from ending up in peoples inboxes. Since the major email providers do not recycle email addresses, the only way you can inherit a spammy email address is if you are using an email address that is connected to a website that you own. By this I mean, you do not use gmail but rather "[email protected]". In this case, fixing the problem can be a lot harder. Someone else has damaged the reputation of this websites email in the past. There are methods you can take to fix this, but more often than not, it is much easier to just purchase a new domain. Before you buy a domain that you plan to use for a business. You should be making sure that you are doing a background check to make sure that the property you are about to purchase doesnt have a dark past.