If you encountered the SMTP error "SMTP Error: [451] Failed to add recipient (Temporary local problem - please try later)" or "SMTP Error: [451] Temporary local problem - please try later" after attempting to install or update the Exim package on CentOS 7, it's important to note that the commands you provided for installing the package may not be directly related to the error message. The error is likely not caused by the package installation itself.
To address the SMTP error, you can follow these steps:
1. Verify network connectivity:
Check if your server has a stable and reliable internet connection.
Confirm if you can access other websites or services from the server.
2.Check mail server configuration:
Review your Exim configuration files, typically located at /etc/exim.conf or /etc/exim/exim.conf.
Make sure the configuration is correctly set up, including the required SMTP settings.
Look for any specific error messages or warnings related to your configuration.
3.Examine mail server logs:
Check the Exim log files, usually found at /var/log/exim/mainlog or /var/log/maillog.
Look for any error messages or additional details about the problem in the logs.
The log files may provide insights into the specific issue you're facing.
4.Check DNS settings:
Verify that your server's DNS settings are correctly configured.
Use the nslookup command to check if domain names or IP addresses resolve correctly.
Ensure that the server can resolve the recipient's email domain properly.
5.Verify firewall settings:
Ensure that your firewall settings allow outgoing SMTP connections.
Check for any rules that might be blocking SMTP traffic and adjust them accordingly.
6.Test with a different recipient email address:
Try sending emails to different recipient addresses to determine if the issue is specific to a particular address or domain.
This can help isolate whether the problem lies with the recipient's email server or your configuration.
7.Temporarily disable any antivirus or firewall software:
If you have any antivirus or firewall software running on your server, temporarily disable them to check if they are interfering with the email delivery.
It's important to note that the provided commands (wget and rpm) for installing the Exim package may not be directly related to the SMTP error you encountered. If the problem persists after trying these steps, I recommend seeking assistance from the CentOS community, Exim support, or consulting with a qualified system administrator who can investigate the issue further based on your specific setup and configuration.