An email blacklist or DNS based black hole list is a database which uses a list of criteria to determine whether the IP address sends legitimate emails or spam. Many email servers or ISPs refer such blacklists to get hold of spammers. Since the blacklists have a list of IP address which are found to be spammers or spam friendly servers. If your IP address is being listed in the black list then emails through that IP address will be considered as spam and would not allow your emails to reach sub...

Greylisting is a term used to defend or to block spam at the sender server. It blocks the spam emails based on the behaviour of the sender server instead of content and images of the email campaign. This term is generally used by URIBL and they maintain a list of greylists, whitelists and blacklists. Procedure to get into a greylist:URIBL say the following on their website - "Greylist is a list which contains domains found in UBE/UCE, and possibly honour opt-out requests. It may include ESPs w...