Core Configuration Files
The Haraka core reads some configuration files to determine a few actions:
- smtp.yaml or smtp.json
If either of these files exist then they are loaded first after log.ini. This file is designed to use the JSON/YAML file overrides documented in Config to optionally provide the entire configuration in a single file.
Contains the maximum SIZE of an email that Haraka will receive.
The list of plugins to load
- listen_host, port - the host and port to listen on (default: ::0 and 25)
- listen - (default: [::0]:25) Comma separated IP:Port addresses to listen on
- inactivity_time - how long to let clients idle in seconds (default: 300)
- nodes - specifies how many processes to fork. The string "cpus" will fork as many children as there are CPUs (default: 0, which disables cluster mode)
- user - optionally a user to drop privileges to. Can be a string or UID.
- group - optionally a group to drop privileges to. Can be a string or GID.
- ignore_bad_plugins - If a plugin fails to compile by default Haraka will stop at load time. If, however, you wish to continue on without that plugin's facilities, then set this config option
- daemonize - enable this to cause Haraka to fork into the background on start-up (default: 0)
- daemon_log_file - (default: /var/log/haraka.log) where to redirect stdout/stderr when daemonized
- daemon_pid_file - (default: /var/run/haraka.pid) where to write a PID file to
- spool_dir - (default: none) directory to create temporary spool files in
- spool_after - (default: -1) if message exceeds this size in bytes, then spool the message to disk specify -1 to disable spooling completely or 0 to force all messages to be spooled to disk.
- graceful_shutdown - (default: false) enable this to wait for sockets on shutdown instead of closing them quickly
- force_shutdown_timeout - (default: 30) number of seconds to wait for a graceful shutdown
- smtputf8 - (default: true) advertise support for SMTPUTF8
- strict_rfc1869 - (default: false) Requires senders to conform to RFC 1869 and RFC 821 when sending the MAIL FROM and RCPT TO commands. In particular, the inclusion of spurious spaces or missing angle brackets will be rejected.
A name to use for this server. Used in received lines and elsewhere. Setup by default to be your hostname.
Each connection and mail in Haraka includes a UUID which is also in most log messages. If you put a
1in this file then every denied mail (either via DENY/5xx or DENYSOFT/4xx return codes) will include the uuid at the start of each line of the deny message in brackets, making it easy to track problems back to the logs.
Because UUIDs are long, if you put a number greater than 1 in the config file, it will be truncated to that length. We recommend a 6 as a good balance of finding in the logs and not making lines too long.
This will add the full UUID to the first line of the SMTP greeting banner.
If clients talk early we punish them with a delay of this many milliseconds default: 1000.
Seconds to allow a plugin to run before the next hook is called automatically default: 30
Note also that each plugin can have a
config/<plugin_name>.timeoutfile specifying a per-plugin timeout. In this file you can set a timeout of 0 to mean that this plugin's hooks never time out. Use this with care.
If the plugin is in a sub-directory of plugins, then you must create this file in the equivalent path e.g. the queue/smtp_forward would need a timeout file in
The greeting line used when a client connects. This can be multiple lines if required (this may cause some connecting machines to fail - though usually only spam-bots).
The maximum number of "Received" headers allowed in an email. This is a simple protection against mail loops. Defaults to 100.
The maximum length of lines in SMTP session commands (e.g. RCPT, HELO etc). Defaults to 512 (bytes) which is mandated by RFC 5321 §220.127.116.11.4. Clients exceeding this limit will be immediately disconnected with a "521 Command line too long" error.
The maximum length of lines in the DATA section of emails. Defaults to 992 (bytes) which is the limit set by Sendmail. When this limit is exceeded the three bytes "\r\n " (0x0d 0x0a 0x20) are inserted into the stream to "fix" it. This has the potential to "break" some email, but makes it more likely to be accepted by upstream/downstream services, and is the same behaviour as Sendmail. Also when the data line length limit is exceeded
transaction.notes.data_line_length_exceededis set to
Maximum concurrency to use when delivering mails outbound. Defaults to 100.
1in this file to temporarily disable outbound delivery. Useful while figuring out network issues or testing.
The bounce message if delivery of the message fails. The default is normally fine. Bounce messages contain a number of template replacement values which are best discovered by looking at the source code.
A list of HAProxy hosts that Haraka should enable the PROXY protocol from. See HAProxy
Defaults to 1000. There's a potential denial of service in large numbers of MIME parts in carefully crafted emails. If this limit is too low for some reason you can increase it by setting a value in this file.