Mail delivery failed to the remote servers

cPRex

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Hey there! It sounds like you have been blocked from sending to that remote server, so there won't be anything you can do on your side to resolve that issue.

You may want to check and see if your server's IP address is listed on any blacklists using a tool like this:


If not, you'll want to reach out to that mail provider using a different address that is not blocked to let them know about this issue.
 

cPRex

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They have a similar tool here where you can enter your server's IP to check the reverse DNS configuration online:


Just enter the IP here, and see if the answer returned is the server's hostname. If not, you can speak with your hosting provider to have that updated as that is controlled on their end.
 

cPRex

Jurassic Moderator
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Oct 19, 2014
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I'm not sure how the RATS site performs their check, but I haven't had MXToolbox steer me wrong on reverse DNS checks yet. If it points back to the hostname of the server (not an individual domain, but the server's hostname) then I believe that setting is fine.

It's important to note that isn't why you would end up on a blacklist, but it's just something they are pointing out.