Emails bouncing sometimes

[UXmedia]

Hi.

I just want to make sure this isnt something on my end.. once in a while I get emails bouncing back. I obfuscated the important info (i think)

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This message was created automatically by mail delivery software.

A message that you sent could not be delivered to one or more of its
recipients. This is a permanent error. The following address(es) failed:

 carshop@cableone.net
   host mx.cableone.net [69.168.106.65]
   SMTP error from remote mail server after initial connection:
   554 5.7.1 [C9] Missing reverse DNS for 72.52.229.156
Reporting-MTA: dns; XXXXXXXXXX.uxmediahouse.com

Action: failed
Final-Recipient: rfc822;XXXXXXXXXX@cableone.net
Status: 5.0.0
Remote-MTA: dns; mx.cableone.net
Diagnostic-Code: smtp; 554 5.7.1 [C9] Missing reverse DNS for 72.52.229.156

From: UX Media House <XXXXXXXXXX@uxmediahouse.com>
Subject: Customer Invoice
Date: April 14, 2021 at 10:34:21 AM MDT
To: "Dale Wilkens (Car Shop)" <XXXXXXXXXX@cableone.net>
Reply-To: UX Media House <XXXXXXXXXX@uxmediahouse.com>

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[Evolve Web Hosting]

Used the tools at mxtoolbox.com and they are blacklisted and there are a few other errors showing up. Looks like the recipient server has issues.

[yggdrasil]

This message is not generated by WHMCS but your email server.

[steven99]

6 hours ago, UXmedia said:

   554 5.7.1 [C9] Missing reverse DNS for 72.52.229.156

There's your problem.  You need to request the host / data center you're using for that server to setup the rDNS record for 72.52.229.156 so it points to your mail server address or hostname for the server -- depending on what you have in the mail server's HELO.

[UXmedia]

19 hours ago, steven99 said:

There's your problem.  You need to request the host / data center you're using for that server to setup the rDNS record for 72.52.229.156 so it points to your mail server address or hostname for the server -- depending on what you have in the mail server's HELO.

Thanks so much!!