This plugin enables the use of TLS (via
STARTTLS) in Haraka.
For this plugin to work you must have SSL certificates installed correctly.
Defaults are shown and can be overridden in
key=tls_key.pem cert=tls_cert.pem dhparam=dhparams.pem
If the directory
config/tls exists, each file within the directory is expected to be a PEM encoded TLS bundle. Generate the PEM bundles in The Usual WayTM by concatenating the key, certificate, and CA/chain certs in that order. Example:
cat example.com.key example.com.crt ca.crt > config/tls/example.com.pem
An example acme.sh deployment script demonstrates how to install Let's Encrypt certificates to the Haraka
Haraka has SNI support. When the remote MUA/MTA presents a servername during the TLS handshake and a TLS certificate with that Common Name matches, that certificate will be presented. If no match is found, the default certificate (see Certificate Files above) is presented.
If you have a purchased certificate, append any intermediate/chained/ca-cert files to the certificate in this order:
- The CA signed SSL cert
- Any intermediate certificates
- The CA root certificate
See also Setting Up TLS
Self Issued (unsigned) Certificate
Create a certificate and key file in the config directory with the following command:
openssl req -x509 -nodes -days 2190 -newkey rsa:2048 -keyout config/tls_key.pem -out config/tls_cert.pem
You will be prompted to provide details of your organization. Make sure the
Common Name is set to your servers Fully Qualified Domain Name, which should
be the same as the contents of your
The following settings can be specified in
Specifies an alternative location for the key file. For multiple keys, use
key= assignment for each. Non-absolute paths are relative to the
To configure a single key and a cert chain, located in the
directory, use the following in
To use multiple pairs of key and cert chain files outside of the haraka
config/ directory, configure instead:
key=/etc/ssl/private/example.com.rsa.key.pem cert=/etc/ssl/private/example.com.rsa.crt-chain.pem key=/etc/ssl/private/example.com.ecdsa.key.pem cert=/etc/ssl/private/example.com.ecdsa.crt-chain.pem
Specifies the location(s) for the certificate chain file. For multiple certificate chains, use
cert= assignment for each. Non-absolute paths are relative to the
config/ directory. See the description of the
key parameter for specific use.
If needed, add this section to the
config/tls.ini file and list any IP ranges that have broken TLS hosts. Ex:
[no_tls_hosts] 192.168.1.3 172.16.0.0/16
The Node.js TLS page has additional information about the following options.
An array of incoming ports on which Haraka will not advertise STARTTLS capability.
For known good TLS hosts, it's possible to force that the outbound mailer will only connect via secure sockets. This makes Haraka use forced TLS instead of opportunistic TLS. For forced TLS, the STARTTLS upgrade must succeed with a valid certificate (overriding
rejectUnauthorized). The list is matched both against the host (MX record or
relay_dest_domains.ini), and the domain name of the email address.
no_tls_hosts, this feature is implemented as an array:
[outbound] force_tls_hosts=172.17.123.1 force_tls_hosts=172.17.124.0/24 force_tls_hosts=mx.example.org force_tls_hosts=example.com
A list of allowable ciphers to use. Example:
See also: Mozilla SSL configuration generator and the SSLlabs Test Page
Specifies minimum allowable TLS protocol version to use. Example:
If unset, the default is node's tls.DEFAULT_MIN_VERSION constant.
(Node.js 11.4+ required, for older instances you can use secureProtocol settings)
If specified, the list of configured ciphers is treated as the cipher priority from highest to lowest. The first matching cipher will be used, instead of letting the client choose. The default is
Specifies the elliptic curve used for ECDH or ECDHE ciphers.
Only one curve can be specified. The default is
prime256v1 (NIST P-256).
Specifies the file containing the diffie-hellman parameters to use for DH or DHE key exchange. If this param or file is missing, it will be generated automatically. Default:
Whether Haraka should request a certificate from a connecting client.
requestCert=[true|false] (default: true)
Reject connections from clients without a CA validated TLS certificate.
rejectUnauthorized=[true|false] (default: false)
rejectUnauthorized=false, require validated TLS certificates on just the specified ports.
Specifies the OpenSSL API function used for handling the TLS session. Choose
one of the methods described at the
OpenSSL API page.
The default is
Specifies that OCSP Stapling should be enabled, according to RFC 6066. Stapling of OCSP messages allows the client to receive these along the TLS session setup instead of delaying the session setup by requiring a separate http connection to the OCSP server.
requestOCSP=[true|false] (default: false)
OCSP responses from the OCSP server are cached in memory for as long as they are valid, and get refreshed after that time. A server restart requires the OCSP responses to be fetched again upon the first client connection.
Inbound Specific Configuration
By default the above options are shared with outbound mail (either
smtp_proxy or plain outbound mail heading to
an external destination). To make these options specific to inbound
mail, put them under an
[inbound] parameter group. Outbound options
can go under an
[outbound] parameter group, and plugins that use
SMTP tls for queueing such as
use that plugin name for plugin specific options.
This section is mainly used to enable so called TLS NO-GO feature that essentially stops advertising/using TLS if there was a problem setting it up previously. We use
no_tls|ip.add.re.ss key to store the flag in redis. There are a couple of settings that control the behavior:
disable_for_failed_hosts = true to enable the feature
disable_expiry = 604800 to set for how long we disable TLS for failing host, in seconds
disable_inbound_expiry = 3600 same as above, but applies to inbound (aka STARTTLS capability) only
- Certificate Files
- Certificate Directory
- Purchased Certificate
- Self Issued (unsigned) Certificate
- Inbound Specific Configuration
- [redis] section