There is a common email delivery issue with most email servers. Before proceeding with trying to solve this issue, it is important to set the PTR for your domain.

We had such a problem with sending email and always received an error message which says "The response from the remote server was: 454 4.7.0 TLS not available due to local problem".

Basically, our email server was unable to receive emails from most email providers such as Gmail , and yahoo. 

Our Server Experts were able to resolve it and the cause and solutions will be outlined here.

Causes

1. Postfix Certificate File Missing.

The 454 4.7.0 TLS issues could occur when the Postfix is not properly configured. Some important postfix certificate file might not be available or broken. Therefore you need to generate it.

2. Incorrect Certificate path.

The location or path of the certificate might be incorrect in the Postfix main configuration file. To rectify this, ensure that the path to the Postfix certificate is set correctly. In most Server Distribution, this can be resolved in the /etc/postfix/main.cf file.

3. TLS configuration settings Missing in Postfix Mail config file.

It is possible for important TLS configuration parameters to be missing.

Possible Solutions

1. Via ssh, create a "tls" Directory in the /etc/postfix/ path of the server with full permission.

2. Generate the missing certificate file in the new Directory created earlier. To generate this, simply run the following command;

$ openssl req -new -x509 -nodes -out smtpd.pem -keyout smtpd.pem -days 3650

3. Add the following necessary postfix parameters in the /etc/postfix/main.cf file;

smtpd_tls_CAfile = /etc/postfix/tls/smtpd.pem

smtpd_tls_cert_file = /etc/postfix/tls/smtpd.pem

smtpd_tls_key_file = /etc/postfix/tls/smtpd.pem

smtpd_tls_session_cache_database = btree:${queue_directory}/smtpd_scache

smtpd_tls_security_level = may

smtpd_use_tls = yes

smtp_tls_security_level = may

smtp_tls_CAfile = /etc/postfix/tls/smtpd.pem

smtp_tls_cert_file = /etc/postfix/tls/smtpd.pem

smtp_tls_key_file = /etc/postfix/tls/smtpd.pem

smtp_tls_session_cache_database = btree:${queue_directory}/smtp_scache

smtp_use_tls = yes

smtpd_tls_received_header = yes

smtpd_tls_ask_ccert = yes

smtpd_tls_loglevel = 1

tls_random_source = dev:/dev/urandom

4. In the case whereby the smtpd_sasl_auth_enable = yes parameter is available in the config file, ensure that the saslauthd service is enabled. To enable this, use the command below;

$ service saslauthd status

5. Finally, you should reboot the Postfix configuration by running the command;

$ service postfix restart

Conclusion

Our Server experts are here to help you resolve "454 4.7.0 TLS not available due to local problem" email issue. You can contact them via Service Page.