When I set up an SMTP for a server. I add RDNS to our server. After successfully runs two-day website up then show me an error like 403. for only one domain. In my server, there are 5 domains running. Only one domain shows me an error which is I use in RDNS.
Setting up mail servers can be like walking into a minefield! To get started troubleshooting your issue, we may need some more information from you. Some useful information you could provide:
- What specific errors are you seeing when you try to connect to your problem domain? Are they 404 or 403? Are there any messages along with those error codes? We encourage posters to copy and paste error output into their posts, as it is super helpful for diagnosing the problem.
- If I understand correctly your problem domain is the one running SMTP services. Can you confirm this? Are there any other services running on that domain?
- All user accounts created after November 5th 2019 automatically block outbound SMTP traffic. Have you completed the process for lifting those restrictions as described in this post?
You may want to consult our guide on Asking Better Questions as well. It provides guidelines for how to share the right information so that you're able to get the answers you need.
Hopefully this gets us started!