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Email Down ALERT
Blacklist ALERT


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Free Blacklist Check
Enter an IP address OR hostname to check against more than 135 blacklists. Test takes less than 5 seconds. This blacklist checker checks all known blacklists (block, black, RBL, spam, virus, zombie, etc.).











Did you know?

Starting at $3/month our Blacklist ALERT will run this check and alert you if your email server is blacklisted?

Our Email Down ALERT tool completes a roundtrip email every few minutes to make sure your entire email system is working.

Deliverability Score

A total score that takes into account all blacklists (all rows) to calculate an overall deliverability score based on the American grading system.

A - This is the best possible result. Your server is not listed on any blacklists or these blacklists are not in use in enough places to block a significant amount of your outbound email.

B - This is an OK result, but you should investigate further. Your server is listed on the blacklist(s) shown. These blacklists are not widely used and will not cause much of your outbound emails to be blocked. Even so, if possible, take steps to remove yourself from these blacklists by following the "More info" link.

C - Your server is listed on at least one blacklist that is moderately used. This will cause some emails not to go through. Follow the "More Info" links to find out how to get off the blacklist.

D - This is a bad result. Many of your emails from this IP will be rejected. This may also be a sign that you will be listed on more blacklists soon. You should resolve the problem (see the More Info link) and then request a delisting directly from the blacklist website or wait until they delist you automatically.

F - Fail. This is a bad result and greatly impacts your ability send email. Many or all of your emails from this IP will be rejected. You should follow the "More info" links to find out why your system is blacklisted. Most likely, your IP is known for sending spam, or possibly there is virus or other problem sending spam from your network. You should resolve the problem and then request a delisting directly from the blacklist website or wait until they delist you automatically.


Key

NOT LISTED (White) - This is a good result. Your server is not listed on the blacklist in that row. Ideally, you will get this for all the rows.

LISTED! (Red) - This is a bad result. Your server is listed on the blacklist in that row. Review your Deliverability Score to see how this affects your ability to send email.

WHITE LISTED (Green)-Your server is listed on a white list (explicitly allowed). Sometimes this can have an unintended, reverse effect, and actually block legitimate emails (a false positive). Many anti-spam systems only look to see if an IP is listed and ignore the return code data (which is where the white list is stated and varies by list), it causes a false positive on a recipient’s email system and blocks your email.

WARNING (Yellow) - Usually followed by "Time out" or "Server did not respond." This means that MailBox Tools was unable to communicate with the blacklist server (for example, Spamhaus). It indicates a problem at the third-party blacklist server and does not affect your deliverability or impact your score. You may safely ignore this result.



How do I get taken off of a blacklist?

MailBox Tools does not maintain any of these blacklists, please do not contact us asking us to remove your server. MailBox Tools provides one convenient place to search them all. If your server is on a blacklist, you will need to click on the More Info link to find out more information. To get off of a blacklist, usually you need to resolve a problem on your end and then submit a delist request on the blacklist's website.