What to do to minimize chances of being blacklisted by DNSBL databases...

Whatever is described below assumes that your server is not an open relay, it is protected by enabling SMTP authentication (Security - AntiSpam - SMTP Authentication is enabled), and none of your users does actual spamming...

To test whether your IP address is blacklisted, use the this page at WhatIsMyIPAddress.com.

If your IP address belongs to a DSL or cable provider, then you are already blacklisted by some DNSBL databases. They consider these IP addresses as ones with low "reputation".

Some DNSBL services blacklist entire ISPs. Make sure to use ISP in "good standing".

If one of IP addresses does spamming, some DNSBLs may blacklist that IP address, and at the same time - their neighbours too...

If you are blacklisted becase of above mentioned problems, there is only one solution: change ISP, and get different IP address with good "reputation".

Here is what you can do to avoid being blacklisted if your ISP and your IP address are not blacklisted because of above listed reasons:

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