Reverse DNS is not a valid Hostname

Hi there,

I am running a DigitalOcean 1-click app setup with Ubuntu and CyberPanel.
I went through all the proper steps to make sure everything is configured, I named my droplet as my domain name to make sure the ptr record is created but now I have no clue what to do. The mailer-test website tells me I have a 10/10 score BUT my mail lands to spam for Gmail, Apple as well as Outlook and on MXToolBox I found a problem:

SMTP Valid Hostname Reverse DNS is not a valid Hostname


Developer recommended to do clean/fresh manual install using ubuntu 20.04

most of provider only give the ptr by request. please contact your provider

No need, figured out the problem. I had to change the droplet name of my server from to which in turn generates a ptr now all my mail lands in the inbox :slight_smile:

Reverse DNS is usually done at hosting provider’s end for the IP address assigned to your server.

Maybe this can help: How do I create a reverse DNS (PTR) Record | DigitalOcean

all sorted out, i just had to change the name of the droplet from to and now everything works, emails dont go to spam! :slight_smile:

there are many reason email goes to spam
include the destination mail server
e.g gmail have different policy with outlook,yahoo,aol etc
that included:

  1. domain name
  2. domain ip (based on RBL public blacklist and local blacklist)
  3. domain hostname server
  4. body content
  5. mail-header (beside number 1,2,3):
  • dkim
  • spf
  • dmarc policy
  1. local policy ( like i mention above )

sometimes we dont get spam mark here, but will get marked spam there…

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