4 .TH SLOCAL %manext1% "%nmhdate%" MH.6.8 [%nmhversion%]
6 slocal \- asynchronously filter and deliver new mail
11 [address\ info\ sender]
22 .\" \%[\-home\ homedir]
27 .RB [ \-verbose " | " \-noverbose ]
28 .RB [ \-suppressdup " | " \-nosuppressdup ]
35 is a program designed to allow you to have your inbound
36 mail processed according to a complex set of selection criteria.
37 You do not normally invoke
41 is invoked on your behalf by your system's Message Transfer Agent
44 when the message arrives.
46 The message selection criteria used by
47 .B slocal is specified
49 .RI \*(lq \&.maildelivery \*(rq
50 in the user's home directory.
51 You can specify an alternate file with the
54 option. The syntax of this file is specified below.
56 The message delivery address and message sender are determined from
57 the Message Transfer Agent envelope information, if possible.
60 the sender will obtained from the UUCP
61 \*(lqFrom:\*(rq line, if present. The user may override these
62 values with command line arguments, or arguments to the
68 The message is normally read from the standard input. The
70 switch sets the name of the file from which the message should be
71 read, instead of reading stdin. This is useful when debugging a
72 .RI \*(lq \&.maildelivery \*(rq
79 the name of the user for
80 whom it is delivering mail. The
84 the name of the user's maildrop file.
87 is able to detect and suppress duplicate messages.
88 To enable this, use the option
92 keep a database containing the Message-ID's of incoming messages,
93 in order to detect duplicates. Depending on your configuration,
94 this database will be in either ndbm or Berkeley db format.
98 switch may be used to pass an arbitrary argument to
101 may invoke on your behalf.
107 to give information on
108 stdout about its progress. The
111 verbose debugging output on stderr. These flags are useful when
112 creating and debugging your
113 .RI \*(lq \&.maildelivery \*(rq
115 allow you to see the decisions and actions that
117 is taking, as well as check for syntax errors in your
118 .RI \*(lq \&.maildelivery \*(rq
121 .SS "Message Transfer Agents"
122 Most modern MTAs including
127 support a \&.forward file for directing incoming mail.
128 You should include the line
131 \*(lq|\ %libdir%/slocal\ \-user\ username\*(rq
133 in your \&.forward file in your home directory. This will cause
136 on your behalf when a message arrives.
138 .SS "The Maildelivery File"
140 .RI \*(lq \&.maildelivery \*(rq
144 incoming mail. Each line of this file consists of five fields, separated
145 by white-space or comma. Since double-quotes are honored, these
146 characters may be included in a single argument by enclosing the entire
147 argument in double-quotes. A double-quote can be included by preceding it
148 with a backslash. Lines beginning with `#' and blank lines are ignored.
150 The format of each line in the
151 .RI \*(lq \&.maildelivery \*(rq
155 .B "header pattern action result string"
160 The name of a header field (such as To, Cc, or From) that is to
161 be searched for a pattern. This is any field in the headers of
162 the message that might be present.
164 The following special fields are also defined:
167 the out-of-band sender information
170 the address that was used to cause delivery to the recipient
175 if the message hasn't been delivered yet
183 The sequence of characters to match in the specified header field.
184 Matching is case-insensitive, but does not use regular expressions.
189 The action to take to deliver the message. When a message is delivered,
190 a \*(lqDelivery\-Date:\ date\*(rq header is added which indicates the date
191 and time that message was delivered.
194 This action always succeeds.
196 .IR file ", " mbox ", or " >
197 Append the message to the file named by
200 appended to the file in mbox (uucp) format. This is the format used by most
201 other mail clients (such as mailx, elm). If the message can be appended to
202 the file, then this action succeeds.
207 but always appends the message using the MMDF mailbox format.
210 Pipe the message as the standard input to the command named by
212 using the Bourne shell
214 to interpret the string.
215 Prior to giving the string to the shell, it is expanded with the following
218 .TP \w'zzreplyztozaaa'u
220 the out-of-band sender information
221 .TP \w'zzreplyztozaaa'u
223 the address that was used to cause delivery to the recipient
224 .TP \w'zzreplyztozaaa'u
226 the size of the message in bytes
227 .TP \w'zzreplyztozaaa'u
229 either the \*(lqReply\-To:\*(rq or \*(lqFrom:\*(rq field of the message
230 .TP \w'zzreplyztozaaa'u
232 the out-of-band information specified
238 but executes the command
239 directly, after built-in variable expansion, without assistance from
240 the shell. This action can be used to avoid quoting special characters
241 which your shell might interpret.
244 Store the message in the
248 Currently this is handled by piping the message to the
252 although this may change in the future.
257 Indicates how the action should be performed:
260 Perform the action. If the action succeeds, then the message
261 is considered delivered.
264 Perform the action. Regardless of the outcome of the action,
265 the message is not considered delivered.
268 Perform the action only if the message has not been delivered.
269 If the action succeeds, then the message is considered delivered.
272 Perform the action only if the message has not been delivered
273 and the previous action succeeded. If this action succeeds, then the
274 message is considered delivered.
276 The delivery file is always read completely, so that several matches
277 can be made and several actions can be taken.
280 .SS "Security of Delivery Files"
281 In order to prevent security problems, the
282 .RI \*(lq \&.maildelivery \*(rq
283 file must be owned either by the user or by root, and must be
284 writable only by the owner. If this is not the case, the file is
288 .RI \*(lq \&.maildelivery \*(rq
289 file cannot be found, or does not
290 perform an action which delivers the message, then
292 will check for a global delivery file at
293 .IR %etcdir%/maildelivery .
294 This file is read according to the same rules. This file must be
295 owned by the root and must be writable only by the root.
297 If a global delivery file cannot be found or does not perform an
298 action which delivers the message, then standard delivery to the
299 user's maildrop is performed.
301 .SS "Example Delivery File"
302 To summarize, here's an example delivery file:
305 .ta \w'default 'u +\w'mh-workersxx 'uC +\w'destroy 'uC +\w'result 'u
307 # .maildelivery file for nmh's slocal
309 # Blank lines and lines beginning with a '#' are ignored
311 # FIELD PATTERN ACTION RESULT STRING
314 # File mail with foobar in the \*(lqTo:\*(rq line into file foobar.log
315 To foobar file A foobar.log
317 # Pipe messages from coleman to the program message-archive
318 From coleman pipe A /bin/message-archive
320 # Anything to the \*(lqnmh-workers\*(rq mailing list is put in
321 # its own folder, if not filed already
322 To nmh-workers folder ? nmh-workers
324 # Anything with Unix in the subject is put into
326 Subject unix file A unix-mail
328 # I don't want to read mail from Steve, so destroy it
329 From steve destroy A \-
331 # Put anything not matched yet into mailbox
332 default \- file ? mailbox
335 * \- pipe R %libdir%/rcvtty
338 .SS "Sub-process environment"
339 When a process is invoked, its environment is: the user/group-ids are
340 set to recipient's ids; the working directory is the recipient's home
341 directory; the umask is 0077; the process has no /dev/tty; the standard
342 input is set to the message; the standard output and diagnostic output are
343 set to /dev/null; all other file-descriptors are closed; the environment
348 are set appropriately, and no other environment variables exist.
350 The process is given a certain amount of time to execute. If the process
351 does not exit within this limit, the process will be terminated with
352 extreme prejudice. The amount of time is calculated as ((size / 60) +
353 300) seconds, where size is the number of bytes in the message (with
354 30 minutes the maximum time allowed).
356 The exit status of the process is consulted in determining the success
357 of the action. An exit status of zero means that the action succeeded.
358 Any other exit status (or abnormal termination) means that the action
361 In order to avoid any time limitations, you might implement a process
364 The parent would return the appropriate
365 value immediately, and the child could continue on, doing whatever it
366 wanted for as long as it wanted. This approach is somewhat risky if
367 the parent is going to return an exit status of zero. If the parent is
368 going to return a non-zero exit status, then this approach can lead to
369 quicker delivery into your maildrop.
374 .ta \w'%etcdir%/ExtraBigFileName 'u
375 ^%etcdir%/mts.conf~^nmh mts configuration file
376 ^$HOME/\&.maildelivery~^The file controlling local delivery
377 ^%etcdir%/maildelivery~^Rather than the standard file
378 ^%mailspool%/$USER~^The default maildrop
382 rcvdist(1), rcvpack(1), rcvstore(1), rcvtty(1), mh\-format(5)
387 .RB ` \-nosuppressdup '
388 .RB ` \-maildelivery "' defaults to $HOME/\&.maildelivery"
389 .RB ` \-mailbox "' deaults to %mailspool%/$USER"
390 .RB ` \-file "' defaults to stdin"
391 .RB ` \-user "' defaults to the current user"
399 was originally designed to be backward-compatible with
405 .RI \*(lq \&.maildelivery \*(rq
406 file syntax is somewhat limited. But
408 has been modified and extended, so that is it no longer compatible with
411 In addition to an exit status of zero, the
417 (9) mean that the message has been fully delivered.
418 Any other non-zero exit status, including abnormal termination, is
424 \*(lquse an alternate route\*(rq (deliver the message to the maildrop).
427 Only two return codes are meaningful, others should be.
430 was originally designed to be backwards-compatible with the
432 functionality provided by