The following options are available:

-V

displays the version of the DCC procmail() interface.

-d

enables debugging output from the DCC client library. Additional -d options increase the number of messages. One causes error messages to be sent to STDERR as well as the system log.

-A

adds to existing X-DCC headers (if any) of the brand of the current server instead of replacing existing headers.

-Q

only queries the DCC server about the checksums of messages instead of reporting and then querying. This is useful when is used to filter mail that has already been reported to a DCC server by another DCC client such as dccm(8) . This can also be useful when applying a private white or black list to mail that has already been reported to a DCC server. No single mail message should be reported to a DCC server more than once per recipient, such as would happen if is not given -Q when processing a stream of mail that has already been seen by a DCC client. Additional reports of a message increase its apparent "bulkness."

-C

outputs only the X-DCC header and the checksums for the message.

-H

outputs only the X-DCC header.

-E

adds lines to the start of the log file turned on with -l and -c describing what might have been the envelope of the message. All of the information for the envelope lines comes from arguments to including -a and -R . No lines are generated for which no information is available, such as the envelope recipient.

-R

says the first Received line has a standard "name (name [IP address])..." format and that the address is the IP address of the SMTP client that would otherwise be provided with -a . If the local SMTP server adds a Received line with some other format or does not add a Received line, the -a option should be used.

-h homedir

overrides the default DCC home directory, which is often /var/dcc.

-m map

specifies a name or path of the memory mapped parameter file instead of the default map in the DCC home directory. It should be created with the new map operation of the cdcc() command.

-w whiteclnt

specifies an optional file containing SMTP client IP addresses and SMTP headers of mail that do not need X-DCC headers and whose checksums should not be reported to the DCC server. It can also contain checksums of spam. If the pathname is not absolute, it is relative to the DCC home directory. Thus, individual users with private whitelists usually specify them with absolute paths. Common whitelists shared by users must be in the DCC home directory or one of its subdirectories and owned by the set-UID user of dccproc . It is useful to include a common or system-wide whitelist in private lists. The format of the whiteclnt file is the same as the whitelist file required by dbclean() and dccm(8) . Unlike dccm, the whitelist is optional. Unless -w is used, uses only the whitelist in the DCC server, which is rarely sufficient. Because the contents of the whiteclnt file are used frequently, a companion file is automatically created and maintained. It has the same pathname but with an added suffix of .dccw . It contains a memory mapped hash table of the main file. A local whitelist entry ("OK) or two or more semi-whitelistings ("OK2") for one of the message's checksums prevents all of the message's checksums from being reported to the DCC server and the addition of a header line by dccproc . Because it is run by or on behalf of a single user, ignores env_To entries in the whiteclnt file. Users who don't want to use shouldn't.

-T tmpdir

changes the default directory for temporary files from the default. The default is the directory specified with -l or the system default if there -l is not used. The system default is often /tmp .

-a IP-address

specifies the IP address (not the host name) of the immediately previous SMTP client. It is often not available. See also -R .

-f env_from

specifies the RFC 821 envelope "Mail From" value with which the message arrived. It is often not available. If -f is not present, the contents of the first Return-Path: or UNIX style From_ header is used. The env_from string is often but need not be bracketed with "<>".

-t targets

specifies the number of addressees of the message if other than 1. The string many instead of a number asserts that there were too many addressees and that the message is unsolicited bulk email.

-x exitcode

specifies the code or status with which exits if the -c thresholds are reached or the -w whiteclnt file blacklists the message, unless the message is whitelisted. The default value is EX_NOUSER. EX_NOUSER is 67 on many systems. Use 0 to always exit successfully.

-c Xo

type, [log-thold,] rej-thold sets logging and "spam" thresholds for checksum type . Each logged message placed in a separate file in the directory specified with -l . The checksum types are IP , env_From , From , Message-ID , Received , Body , Fuz1 , and Fuz2 . The string ALL sets thresholds for all types, but is unlikely to be useful except for setting logging thresholds. The string CMN specifies the commonly used checksums Body , Fuz1 , and Fuz2 . Rej-thold and log-thold must be numbers, the string NEVER , or the string MANY indicating millions of targets. Counts from the DCC server as large as the threshold for any single type are taken as sufficient evidence that the message should be logged or rejected. Log-thold is the threshold at which messages are logged. It can be handy to log messages at a lower threshold to find solicited bulk mail sources such as mailing lists. Messages that reach at least one of their rejection thresholds or that have complicated combinations of white- and blacklisting are logged regardless of logging thresholds. Rej-thold is the threshold at which messages are considered "bulk," and so should cause the X-DCC header line to contain the string "bulk" and to exit with the value set by -x . The checksums of locally white-listed messages are not checked with the DCC server and so only the number of targets of the current instance of a white-listed message are compared against the thresholds. The default is -c ALL,NEVER , so that nothing is discarded or logged. A common choice is -c CMN,25,50 to reject or discard mail with common bodies except as overridden by the whitelist of the DCC server and -g and -w .

-g Xo

[not-] type indicates that white-listed, OK or OK2 , counts from the DCC server for a type of checksum are to be believed. They should be ignored if prefixed with not- . Type is one of the same set of strings as for -c . Only IP , env_From , and From are likely choices. By default all three are honored, and hence the need for not- .

-S hdr

adds to the list of substitute or locally chosen headers that are checked with the -w whiteclnt file and sent to the DCC server. The checksum of the last header of type hdr found in the message is checked. As many as 6 different substitute headers can be specified, but only the checksum of the first of the 6 will be sent to the DCC server.

-i infile

specifies an input file for the entire message instead of standard input. If not absolute, the pathname is interpreted relative to the directory in which was started.

-o outfile

specifies an output file for the entire message including headers instead of standard output. If not absolute, the pathname is interpreted relative to the directory in which was started.

-l logdir

specifies a directory for copies of messages whose checksum target counts exceed -c thresholds. The format of each file is affected by -E . If logdir is not an absolute path, it is relative to the directory in which is started. If logdir starts with log files are put into subdirectories of the form logdir/JJJ where JJJ is the current julian day. H?logdir puts logs files into subdirectories of the form logdir/JJJ/HH where HH is the current hour. M?logdir puts log files into subdirectories of the form logdir/JJJ/HH/MM where MM is the current minute. See the FILES section below concerning the contents of the files. The directory is relative to the DCC home directory if it is not absolute

-B dnsbl-option

enables DNS blacklist checks of the SMTP client IP address, SMTP envelope Mail_From sender domain name, and of host names in URLs in the message body. Body URL blacklisting has far too many false positives to use on abuse mailboxes. It is less effective than greylisting with dccm() or dccifd() but can be useful in situations where greylisting cannot be used. Dnsbl-option is either of the form set:option or of the form domain Ns [,IPaddr Ns [,bltype .]] Domain is a DNS blacklist domain such as example.com that will be searched. IPaddr is the IP address in the DNS blacklist that indicates that the mail message is spam. 127.0.0.1 is assumed if IPaddr is absent. IPv6 addresses can be specified with the usual colon (:) notation. Names can be used instead of numeric addresses. The type of DNS blacklist is specified by bltype as name , IPv4 , or IPv6 . Given an envelope sender domain name or a domain name in a URL of spam.domain.org and a blacklist of type name , spam.domain.org.example.com will be tried. Blacklist types of IPv4 and IPv6 require that the domain name in a URL be resolved into an IPv4 or IPv6 address. The address is then written as a reversed string of decimal octets to check the DNS blacklist, as in 2.0.0.127.example.com, More than one blacklist can be specified. They are searched in order. All searching is stopped at the first positive result. Positive results are ignored after being logged unless an option DNSBL-on line appears in the global or per-user whiteclnt file. -B set:debug sends more messages about all DNS resolutions to the system log. -B set:msg-secs=S limits to S seconds total for checking all DNS blacklists. The default is 20. -B set:URL-secs=S limits to at most S seconds resolving and checking any single URL. The default is 5. Some spam contains dozens of URLs and that some "spamvertised" URLs contain host names that need minutes to resolve. Busy mail systems cannot afford to spend minutes checking each incoming mail message. In order to use typical single-threaded DNS resolver libraries, dccm() and dccifd() use fleets of helper processes. -B set:no-envelope says that SMTP client IP addresses and sender Mail_From domain names should not be checked in the following blacklists. -B set:envelope restores the default for subsequently named blacklists. -B set:no-body says that URLs in the message body should not be checked in the in the following blacklists. -B set:body restores the default for later blacklists. -B set:no-MX says MX servers of sender Mail_From domain names and host names in URLs should not be checked in the following blacklists. -B set:MX restores the default.

-L ltype,facility.level

specifies how messages should be logged. Ltype must be error or info to indicate which of the two types of messages are being controlled. Level must be a syslog() level among EMERG , ALERT , CRIT , ERR , WARNING , NOTICE , INFO , and DEBUG . Facility must be among AUTH , AUTHPRIV , CRON , DAEMON , FTP , KERN , LPR , MAIL , NEWS , USER , UUCP , and LOCAL0 through LOCAL7 . The default is equivalent to Something like this turns off the log messages:

exits 0 on success and with the -x value if the -c thresholds are reached or the -w whiteclnt file blacklists the message. If at all possible, the input mail message is output to standard output or the -o outfile despite errors. If possible, error messages are put into the system log instead of being mixed with the output mail message. The exit status is zero for errors so that the mail message will not be rejected.