Basically your sending IP address has been listed by a popular blacklist as likely to send Spam and therefore they have listed your email address on their “blacklist.”Once this occurs mail administrators and individuals that use this list as an IP block list will not take receipt of your email, send it to a junk folder, delete it etc. If an independent group thinks that your message has some spammy characteristics they may or may not add you to their list. A number of the blacklists select with an algorithm that is independent of human selection. Bottom line selection can be arbitrary and every legitimate marketer should be aware of this potential delivery rate pitfall.

First of all check if you are or not. Use a service like www.emailreach.com. Once confirmed that you have been wrongly assigned as spam there are number of things you can do. We strongly recommend you working to understand what characteristic caused you to be listed, and working to remove this trait from your campaigns. Typical issues are incorrect mail administrator settings, using a non-dedicated deployment machine, sending large volumes of mail in short periods. Once this is corrected reach out to the blacklist and request to be whitelisted. This often is easier if a third party request on your behalf. Whitelisting takes time far better to avoid blacklists in the first place.