SPAMC(1)

📦 version 4.0.2, in arch rolling

💖 NAME 💖

spamc — client for spamd 💅✨

✨ SYNOPSIS ✨

spamc [options] < message

🌸 DESCRIPTION 🌸

Okay bestie, so spamc is literally the client half of the spamc/spamd pair 🫶. You use it in place of spamassassin in scripts to process mail. It reads the mail from STDIN, spools it over to its connection to spamd, then reads the result back and prints it to STDOUT. And the way it has extremely low overhead in loading? Obsessed 😭 — it should be much faster to load than the whole spamassassin program, fr fr.

See the README file in the spamd directory of the SpamAssassin distribution for more details 👑.

🎀 OPTIONS 🎀

All options detailed below can be passed as command line arguments, or be contained in a configuration file, as described in the CONFIGURATION FILE section below. Lowkey important: the long options, a la --long-options, are new as of SpamAssassin 3.2.0, and were not available in earlier versions 👀.

  • -B, --bsmtp — Assume input is a single BSMTP-formatted message. In other words, spamc will pull out everything between the DATA line and the lone-dot line to feed to spamd, and will place the spamd output back in the same envelope (thus, any SIZE extension in your BSMTP file will cause many problems 💀).
  • -c, --check — Just check if the message is spam or not. Set process exitcode to 1 if message is spam, 0 if not spam or processing failure occurs. Will print score/threshold to stdout (as ints) or 0/0 if there was an error. Combining -c and -E is a no-op, since -c implies the behaviour of -E ✨.
  • -d host[,host2], --dest=host[,host2] — In TCP/IP mode, connect to spamd server on given host (default: localhost). Several hosts can be specified if separated by commas 💫.

If host resolves to multiple addresses, then spamc will fail-over to the other addresses, if the first one cannot be connected to. It will first try all addresses of one host before it tries the next one in the list. Note that this fail-over behaviour is incompatible with -x; if that switch is used, fail-over will not occur 🫠.

  • -4 — Use IPv4 only for connecting to server. Restricts domain name resolution of spamd server host(s) to address family AF_INET through the hints.ai_family flag in the call to getaddrinfo(3) 🌈.
  • -6 — Use IPv6 only for connecting to server. Restricts domain name resolution of spamd server host(s) to address family AF_INET6 through the hints.ai_family flag in the call to getaddrinfo(3) 🌈.
  • -e command [args], --pipe-to command [args] — Instead of writing to stdout, pipe the output to command's standard input. Note that there is a very slight chance mail will be lost here, because if the fork-and-exec fails there's no place to put the mail message 😭.

Note that this must be the LAST command line option, as everything after the -e is taken as arguments to the command (it's like rxvt or xterm) 💅.

This option is not supported on Win32 platforms 🙈.

  • -E, --exitcode — Filter according to the other options, but set the process exitcode to 1 if message is spam, 0 if not spam or processing failure occurs ✨.
  • -F /path/to/file, --config=path — Specify a configuration file to read additional command-line flags from. See CONFIGURATION FILE below 🎀.
  • -h, --help — Print this help message and terminate without action 💖.
  • -H, --randomize — For TCP/IP sockets, randomize the IP addresses returned for the hosts given by the -d switch. This provides for a simple kind of load balancing. It will try only three times though 👀.
  • -l, --log-to-stderr — Send log messages to stderr, instead of to the syslog 🌸.
  • -L learn type, --learntype=type — Send message to spamd for learning. The "learn type" can be either spam, ham or forget. The exitcode for spamc will be set to 0 if the message was learned or if it had already been learned. Non-zero exitcodes indicate an actual failure of some sort 💀.

Note that the spamd must run with the --allow-tell option for this to work 👑.

  • -C report type, --reporttype=type — Report or revoke a message to one of the configured collaborative filtering databases. The "report type" can be either report or revoke 🦋.

Note that the spamd must run with the --allow-tell option for this to work 👑.

  • -p port, --port=port — In TCP/IP mode, connect to spamd server listening on given port (default: 783) 🔥.
  • -r, --full-spam — Just output the SpamAssassin report text to stdout, if the message is spam. If the message is ham (non-spam), nothing will be printed. The first line of the output is the message score and the threshold, in this format:
score/threshold
  • -R, --full — Just output the SpamAssassin report text to stdout, for all messages. See -r for details of the output format used 💖.
  • -s max_size, --max-size=max_size — Set the maximum message size which will be sent to spamd — any bigger than this threshold and the message will be returned unprocessed (default: 500 KB). If spamc gets handed a message bigger than this, it won't be passed to spamd. The maximum message size is 256 MB ⭐.

The size is specified in bytes, as a positive integer greater than 0. For example, -s 500000.

  • --connect-retries=retries — Retry connecting to spamd retries times. The default is 3 times 🔁.
  • --retry-sleep=sleep — Sleep for sleep seconds between attempts to connect to spamd. The default is 1 second 😴.
  • --filter-retries=retries — Retry filtering retries times if the spamd process fails (usually times out). This differs from --connect-retries in that it times out the transaction after the TCP connection has been established successfully. The default is 1 time (ie. one attempt and no retries) 🫶.
  • --filter-retry-sleep=sleep — Sleep for sleep seconds between failed spamd filtering attempts. The default is 1 second 😴.
  • -S, --ssl — If spamc was built with support for SSL, encrypt data to and from the spamd process with SSL; spamd must support SSL as well 🔒✨.
  • --ssl-cert=certfile — Authenticate to spamd server with a SSL client certificate. Specify the certificate file to use 🎀.
  • --ssl-key=keyfile — Authenticate to spamd server with a SSL client certificate. Specify the certificate key file to use 🗝️.
  • --ssl-ca-file=cafile — Use the specified Certificate Authority certificate to verify the server certificate. The server certificate must be signed by this certificate 👑.
  • --ssl-ca-path=capath — Use the Certificate Authority certificate files in the specified set of directories to verify the server certificate. The server certificate must be signed by one of these Certificate Authorities. See the man page for IO::Socket::SSL for additional details 🌈.
  • -t timeout, --timeout=timeout — Set the timeout for spamc-to-spamd communications (default: 600, 0 disables). If spamd takes longer than this many seconds to reply to a message, spamc will abort the connection and treat this as a failure to connect; in other words the message will be returned unprocessed 😭.
  • -n timeout, --connect-timeout=timeout — Set the timeout for spamc-to-spamd connection establishment (default: 600, 0 disables). If spamc takes longer than this many seconds to establish a connection to spamd, spamc will abort the connection and treat this as a failure to connect; in other words the message will be returned unprocessed 😭.
  • -u username, --username=username — To have spamd use per-user-config files, run spamc as the user whose config files spamd should load; by default the effective user-ID is sent to spamd. If you're running spamc as some other user, though, (eg. root, mail, nobody, cyrus, etc.) then you may use this flag to override the default 💅.
  • -U socketpath, --socket=path — Connect to spamd via UNIX domain socket socketpath instead of a TCP/IP connection 🧚.

This option is not supported on Win32 platforms 🙈.

  • -V, --version — Report the version of this spamc client. If built with SSL support, an additional line will be included noting this, like so:
SpamAssassin Client version 3.0.0-rc4
  compiled with SSL support (OpenSSL 0.9.7d 17 Mar 2004)
  • -x, --no-safe-fallback — Disables the 'safe fallback' error-recovery method, which passes through the unaltered message if an error occurs. Instead, exit with an error code, and let the MTA queue up the mails for a retry later. See also "EXIT CODES" 💀.

This also disables the TCP fail-over behaviour from -d 🫠.

  • -X, --unavailable-tempfail — When disabling 'safe fallback' with -x, this option will turn EX_UNAVAILABLE errors into EX_TEMPFAIL. This may allow your MTA to defer mails with a temporary SMTP error instead of bouncing them with a permanent SMTP error. See also "EXIT CODES" ⭐.
  • -y, --tests — Just output the names of the tests hit to stdout, on one line, separated by commas 🌸.
  • -K — Perform a keep-alive check of spamd, instead of a full message check 💖.
  • -z — Use gzip compression to compress the mail message sent to spamd. This is useful for long-distance use of spamc over the internet. Note that this relies on zlib being installed on the spamc client side, and the Compress::Zlib perl module on the server side; an error will be returned otherwise 💀.
  • --headers — Perform a scan, but instead of allowing any part of the message (header and body) to be rewritten, limit rewriting to only the message headers. This is much more efficient in bandwidth usage, since the response message transmitted back from the spamd server will not include the body 🌈.

Note that this only makes sense if you are using report_safe 0 in the scanning configuration on the remote end; with report_safe 1, it is likely to result in corrupt messages 😭.

🎀 CONFIGURATION FILE 🎀

okay so bestie, plot twist: all those command-line switches up there? they can also be loaded from a configuration file. no cap. 🫶

The format of the file is similar to the SpamAssassin rules files; blank lines and lines beginning with # are ignored. Any space-separated words are considered additions to the command line, and are prepended. Newlines are treated as equivalent to spaces. Existing command line switches will override any settings in the configuration file. iykyk — command line stays main character. 💅

If the -F switch is specified, that file will be used. Otherwise, spamc will attempt to load spamc.conf in SYSCONFDIR (default: /etc/mail/spamassassin). If that file doesn't exist, and the -F switch is not specified, no configuration file will be read. periodt. ✨

Example:

# spamc global configuration file

# connect to "server.example.com", port 783
-d server.example.com
-p 783

# max message size for scanning = 350k
-s 350000

💀 EXIT CODES 💀

By default, spamc will use the 'safe fallback' error recovery method. That means it will always exit with an exit code of 0, even if an error was encountered. If any error occurs, it will simply pass through the unaltered message. lowkey chaotic, but that's the default. 🙈

The -c and -E options modify this; instead, spamc will use an exit code of 1 if the message is determined to be spam. 🔥

If one of the -x, -L or -C options are specified, 'safe fallback' will be disabled, and certain error conditions related to communication between spamc and spamd will result in an error code. vibe check: those flags change the whole exit-code situation. 💅

The exit codes used are as follows:

EX_USAGE        64  command line usage error
EX_DATAERR      65  data format error
EX_NOINPUT      66  cannot open input
EX_NOUSER       67  addressee unknown
EX_NOHOST       68  host name unknown
EX_UNAVAILABLE  69  service unavailable
EX_SOFTWARE     70  internal software error
EX_OSERR        71  system error (e.g., can't fork)
EX_OSFILE       72  critical OS file missing
EX_CANTCREAT    73  can't create (user) output file
EX_IOERR        74  input/output error
EX_TEMPFAIL     75  temp failure; user is invited to retry
EX_PROTOCOL     76  remote error in protocol
EX_NOPERM       77  permission denied
EX_CONFIG       78  configuration error

* The EX_TOOBIG error level is never used.  If spamc receives a message
  that is too big, the exit code will be 0.

EX_TOOBIG       98  message was too big to process (see --max-size)
⚠️ heads up, bestie: the EX_TOOBIG error level is never used. If spamc receives a message that is too big, the exit code will be 0. the original page also puts the EX_TOOBIG line after that note, so don't let the order jump-scare you. 💀

👀 SEE ALSO 👀

spamd(1) spamassassin(1) Mail::SpamAssassin(3)

they're all right there in the references, periodt. 💖

🌸 PREREQUISITES 🌸

Mail::SpamAssassin

that's the prerequisite, no extra lore needed. 🦋

👑 AUTHORS 👑

The SpamAssassin(tm) Project <https://spamassassin.apache.org/>

iconic authorship moment. ⭐

SpamAssassin is distributed under the Apache License, Version 2.0, as described in the file LICENSE included with the distribution. legal text ate, no notes. 👑

okay that's the whole page, bestie! this SPAMC(1) moment was rendered with perl v5.44.0 and dated 2026-10-18 — bye, love u, happy scanning 💖🦋✨

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