How do I troubleshoot email delivery issues on my VPS?

Hello everyone,

I am experiencing some email delivery issues on my Virtual Private Server (VPS) and would like to get some advice on troubleshooting the problem such as:

Checked my email server settings and verified that the SMTP and IMAP/POP3 settings are correct?
Verified that my email client settings are correct and pointing to the correct server and port numbers?
Checked my DNS settings and verified that the MX records for my domain are pointing to the correct IP address?

I would appreciate any advice or suggestions on what else I could try to check if it has the problem on my server hosting.

Thank you in advance for your help!

Hi Dopani,

Run some additional checks to pinpoint the issue. Somtimes, it may take a while before you find what is causing the problem.

1. Check if your IP address is blacklisted: Your IP address may have been blacklisted by spam filters, which can prevent your emails from reaching their intended recipients. You can check if your IP address is blacklisted using online tools such as MX Toolbox or Spamhaus.
   
   
2. Check if your email server's IP address is correctly configured: Your email server's IP address must be correctly configured in your domain's DNS records. You can verify this by using the "nslookup" command to check if the domain's MX record points to the correct IP address.
   
   
3. Check if your email server is properly configured for outgoing email: Ensure that your email server is properly configured to send outgoing email. You can do this by verifying that your email server's outgoing SMTP settings are correctly configured and that your server's IP address is not on any email blacklist.
   
   
4. Check your firewall settings: Your VPS may have a firewall that is blocking outgoing email traffic. Check your firewall settings to ensure that outgoing email traffic is allowed.
   
   
5. Check email logs: Review your email server logs to see if there are any errors or issues that may be causing email delivery problems.
   
   
6. Test with a different email client or server: Try sending emails from a different email client or server to see if the issue is specific to your VPS or your email client.

Hi Dopani,

Dopani said:

Checked my email server settings and verified that the SMTP and IMAP/POP3 settings are correct?

Click to expand...

To validate your email server settings, start by confirming the accuracy of your SMTP (outgoing server) and IMAP/POP3 (incoming server) configurations. Cross-check server addresses, port numbers, and security protocols (SSL/TLS) to ensure they match the details provided by your email service provider. Additionally, test the settings by sending and receiving emails to verify that your email server is functioning correctly. This step helps prevent email delivery issues and ensures smooth communication through your
email client.

Dopani said:

Verified that my email client settings are correct and pointing to the correct server and port numbers?

Click to expand...

To verify your email client settings, double-check that they accurately point to the correct server (SMTP and IMAP/POP3) and port numbers. Ensure these settings align with the configurations provided by your email service provider. Confirming their accuracy is crucial to guarantee that your email client can connect to the server correctly, send, and receive emails without issues.

Dopani said:

Checked my DNS settings and verified that the MX records for my domain are pointing to the correct IP address?

Click to expand...

To confirm the accuracy of your DNS settings, specifically the MX (Mail Exchanger) records for your domain, ensure they are correctly pointing to the designated IP address of your email server. This verification guarantees that incoming emails are directed to the appropriate destination, preventing mail delivery problems and ensuring seamless communication through your email server.

If you've always sent emails successfully, you might be puzzled to see your message returned to you with this message: Mail delivery failed: returning...

Simply login to cPanel -> Track Delivery. It'll show you exactly what's going on with all of your email: This is actually one of the first things our support techs are going to do if you call in with mail problems as it will likely show if any server-side errors are happening

Dopani said:

Hello everyone,

I am experiencing some email delivery issues on my Virtual Private Server (VPS) and would like to get some advice on troubleshooting the problem such as:

Checked my email server settings and verified that the SMTP and IMAP/POP3 settings are correct?
Verified that my email client settings are correct and pointing to the correct server and port numbers?
Checked my DNS settings and verified that the MX records for my domain are pointing to the correct IP address?

I would appreciate any advice or suggestions on what else I could try to check if it has the problem on my server hosting.

Thank you in advance for your help!

Click to expand...

Checking your email server settings and verifying your client configurations is a good start. Ensure that your SMTP and IMAP/POP3 settings are correct, including the appropriate port numbers and SSL/TLS settings.

Confirm your DNS settings, with special attention to MX records. These records direct email routing, so make sure they point correctly to your VPS's IP address. Don't forget to review SPF, DKIM, and DMARC records as they play a vital role in email authentication and deliverability.

Evaluate your VPS's IP reputation by using online tools to check for any blacklisting. If your server's IP address is listed, reach out to your hosting provider to resolve the issue and improve its email delivery reputation.

Inspect your server's firewall settings and port configurations. Ensure that email ports such as 25 (SMTP), 110 (POP3), and 143 (IMAP) are open and not blocked to prevent email traffic issues caused by firewall restrictions.

I hope it helps!