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 18.104.22.168.
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.
That's all! See you.