Let's Fix This Together


There is no service in the world that provides a more in-depth analysis of your deliverability than we do. We've made this "our thing" so we make sure we do it well....




Note: Not only do we CHECK for these issues, we provide 24/7 MONITORING of these as well....


Content Analysis Phrasing, trip words, blacklisted images and words, hex-encoded whitespace triggers, excess spacing, broken HTML, missing HTML tags, content balance, colors, div and css issues, off-site css issues, man-in-the-middle poisoning, page loading issues, web server excess spills, combination word/phrase triggers, waterfall blocks, carousel triggers, and much more


DNS Analysis (timing, response agreements, rDNS issues, blocks on DNS, blocks on rDNS, poisoned caches, fragmented cache responses, poisoned 3rd party data, blacklisted DKIM references, blacklisted SPF references, blocks on SPF data, blocks on DMARC pointers, cache laggards, foreign country DNS blocks, out-of-range settings, and more, including proprietary checks which ISP's have advised us are part of their filtering.


Blacklist Analysis 913 known blacklists (combination of IP and domain), 47 "sub-terranean lists" used by major ISPs for filtering, MSSS probes (for Microsoft analysis), Yahoo/AOL known blockfeeders, known Gmail content triggers, 9 third-party reputation beacon systems, and more lists as they are discovered [often weekly].


Whitelist Analysis 61 known locations examined, 14 whitelist detractor sites (feeds negative data to whitelists), IP and Domain probes into all ISP-based whitelists, content tests into all ISPs for behavior analysis, and several proprietary probes we issue to all ISPs for whitelist status determination.


Proprietary Analysis These are techniques we have proven to help us uncover "hard coded entries" made by blacklist owners, ISP's, and third parties. The blocks may be due the type of business you run, your political affiliation (yes, they secretly block because of that, too), outsiders "getting even" with you or one of your staff (common in the IT industry), disgruntled employees reporting false spam-related/abuse issues causing special blocks, etc. These are some of the most damaging blacklists your company can be on yet only a handful of people know where to look to find those type of entries.




More items will be listed on this page as we add them to our service. However, there are many techniques, services, and lists we uncover every week which may not be listed here but will be performed when we analyze your campaigns.




Stuff our lawyers said to mention: ListWorker cannot provide you or your company any guarantees that we can help you cure any problems - because (1) we do not know what you did in the past, (2) we do not know the history of the IP/network space you are using, and (3) we do not know the history of your upstream network provider/host. Something so terrible may have been done that your network is in a permablock state. Usage of our service does not provide any guarantees of improved deliverability or increased sales or profits of any kind. However, we will turn over every stone, search in every hidden corner of the internet, and will do our absolute best to find the issues causing you problems. We will guide you along the way to try and resolve these issues with ease.


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