If you are setting up a mail server at home, you will wonder why the recipient cannot receive your email which is sent by your mail server. The reason is that your IP is blacklisted.
How to overcome this problem? It is quiet easy and just send a request to the Spamhaus.org to cancel your IP from the blacklist. For example, your IP is 219.192.114.214.

http://spamhaus.org/query/bl?ip=219.192.114.214

If you find any item is in red colour (e.g. PBL), your IP is blacklisted. You just click on the link under the red coloured item. Then, select "Remove an IP from PBL" button. Usually, SBL and XBL are in green colour.

Accepted the agreement and click "Remove IP address" button. Finally, fill in the blanks and wait for the confirmation email for the confirmation code to fill into the screen provided after you sent the request.

Make sure your email address is not a web based free account, such as gmail, hotmail, or yahoo and etc.