Postfix TLS Not Working: Cannot Load Certificate or Private Key

Issue

• Postfix disables TLS support when it fails to load the TLS certificate or private key.

• Postfix fails to enable TLS and logs warnings similar to:

   warning: No private key found in /etc/pki/tls/certs/combinedcertkey.pem
   warning: error loading private keys and certificates from: /etc/pki/tls/certs/combinedcertkey.pem: disabling TLS support
  

• When TLS fails in Postfix due to missing or inaccessible certificate/private key files, you may see warnings similar to:

  Jul 28 12:30:09 postfixrhel postfix/smtpd[41095]: warning: cannot get RSA certificate from file "/etc/pki/tls/certs/postfix.pem": disabling TLS support
  Jul 28 12:30:09 postfixrhel postfix/smtpd[41095]: warning: TLS library problem: error:02001002:system library:fopen:No such file or directory:crypto/bio/bss_file.c:288:fopen('/etc/pki/tls/certs/postfix.pem','r'):
  Jul 28 12:30:09 postfixrhel postfix/smtpd[41095]: warning: TLS library problem: error:20074002:BIO routines:file_ctrl:system lib:crypto/bio/bss_file.c:290:
  Jul 28 12:30:09 postfixrhel postfix/smtpd[41095]: warning: TLS library problem: error:140DC002:SSL routines:use_certificate_chain_file:system lib:ssl/ssl_rsa.c:596:
  

  Jul 28 12:55:25 postfixrhel postfix/smtpd[25439]: warning: cannot get RSA private key from file "/etc/pki/tls/private/postfix.key": disabling TLS support
  Jul 28 12:55:25 postfixrhel postfix/smtpd[25439]: warning: TLS library problem: error:80000002:system library::No such file or directory:crypto/bio/bss_file.c:288:calling fopen(/etc/pki/tls/private/postfix.key, r):
  Jul 28 12:55:25 postfixrhel postfix/smtpd[25439]: warning: TLS library problem: error:10080002:BIO routines::system lib:crypto/bio/bss_file.c:291:
  Jul 28 12:55:25 postfixrhel postfix/smtpd[25439]: warning: TLS library problem: error:0A080002:SSL routines::system lib:ssl/ssl_rsa.c:410: