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
134 in your \&.forward file in your home directory. This will cause
137 on your behalf when a message arrives.
139 .SS "The Maildelivery File"
141 .RI \*(lq \&.maildelivery \*(rq
145 incoming mail. Each line of this file consists of five fields, separated
146 by white-space or comma. Since double-quotes are honored, these
147 characters may be included in a single argument by enclosing the entire
148 argument in double-quotes. A double-quote can be included by preceding it
149 with a backslash. Lines beginning with `#' and blank lines are ignored.
151 The format of each line in the
152 .RI \*(lq \&.maildelivery \*(rq
156 .B header pattern action result string
161 The name of a header field (such as To, Cc, or From) that is to
162 be searched for a pattern. This is any field in the headers of
163 the message that might be present.
165 The following special fields are also defined:
168 the out-of-band sender information
171 the address that was used to cause delivery to the recipient
176 if the message hasn't been delivered yet
184 The sequence of characters to match in the specified header field.
185 Matching is case-insensitive, but does not use regular expressions.
190 The action to take to deliver the message. When a message is delivered,
191 a \*(lqDelivery\-Date:\ date\*(rq header is added which indicates the date
192 and time that message was delivered.
195 This action always succeeds.
197 .IR file ", " mbox ", or " >
198 Append the message to the file named by
201 appended to the file in mbox (uucp) format. This is the format used by most
202 other mail clients (such as mailx, elm). If the message can be appended to
203 the file, then this action succeeds.
208 but always appends the message using the MMDF mailbox format.
211 Pipe the message as the standard input to the command named by
213 using the Bourne shell
215 to interpret the string.
216 Prior to giving the string to the shell, it is expanded with the following
219 .TP \w'zzreplyztozaaa'u
221 the out-of-band sender information
222 .TP \w'zzreplyztozaaa'u
224 the address that was used to cause delivery to the recipient
225 .TP \w'zzreplyztozaaa'u
227 the size of the message in bytes
228 .TP \w'zzreplyztozaaa'u
230 either the \*(lqReply\-To:\*(rq or \*(lqFrom:\*(rq field of the message
231 .TP \w'zzreplyztozaaa'u
233 the out-of-band information specified
239 but executes the command
240 directly, after built-in variable expansion, without assistance from
241 the shell. This action can be used to avoid quoting special characters
242 which your shell might interpret.
245 Store the message in the
249 Currently this is handled by piping the message to the
253 although this may change in the future.
258 Indicates how the action should be performed:
261 Perform the action. If the action succeeds, then the message
262 is considered delivered.
265 Perform the action. Regardless of the outcome of the action,
266 the message is not considered delivered.
269 Perform the action only if the message has not been delivered.
270 If the action succeeds, then the message is considered delivered.
273 Perform the action only if the message has not been delivered
274 and the previous action succeeded. If this action succeeds, then the
275 message is considered delivered.
277 The delivery file is always read completely, so that several matches
278 can be made and several actions can be taken.
281 .SS "Security of Delivery Files"
282 In order to prevent security problems, the
283 .RI \*(lq \&.maildelivery \*(rq
284 file must be owned either by the user or by root, and must be
285 writable only by the owner. If this is not the case, the file is
289 .RI \*(lq \&.maildelivery \*(rq
290 file cannot be found, or does not
291 perform an action which delivers the message, then
293 will check for a global delivery file at
294 .IR %etcdir%/maildelivery .
295 This file is read according to the same rules. This file must be
296 owned by the root and must be writable only by the root.
298 If a global delivery file cannot be found or does not perform an
299 action which delivers the message, then standard delivery to the
300 user's maildrop is performed.
302 .SS "Example Delivery File"
303 To summarize, here's an example delivery file:
306 .ta \w'default 'u +\w'mh-workersxx 'uC +\w'destroy 'uC +\w'result 'u
308 # .maildelivery file for nmh's slocal
310 # Blank lines and lines beginning with a '#' are ignored
312 # FIELD PATTERN ACTION RESULT STRING
315 # File mail with foobar in the \*(lqTo:\*(rq line into file foobar.log
316 To foobar file A foobar.log
318 # Pipe messages from coleman to the program message-archive
319 From coleman pipe A /bin/message-archive
321 # Anything to the \*(lqnmh-workers\*(rq mailing list is put in
322 # its own folder, if not filed already
323 To nmh-workers folder ? nmh-workers
325 # Anything with Unix in the subject is put into
327 Subject unix file A unix-mail
329 # I don't want to read mail from Steve, so destroy it
330 From steve destroy A \-
332 # Put anything not matched yet into mailbox
333 default \- file ? mailbox
336 * \- pipe R %libdir%/rcvtty
339 .SS "Sub-process environment"
340 When a process is invoked, its environment is: the user/group-ids are
341 set to recipient's ids; the working directory is the recipient's home
342 directory; the umask is 0077; the process has no /dev/tty; the standard
343 input is set to the message; the standard output and diagnostic output are
344 set to /dev/null; all other file-descriptors are closed; the environment
349 are set appropriately, and no other environment variables exist.
351 The process is given a certain amount of time to execute. If the process
352 does not exit within this limit, the process will be terminated with
353 extreme prejudice. The amount of time is calculated as ((size / 60) +
354 300) seconds, where size is the number of bytes in the message (with
355 30 minutes the maximum time allowed).
357 The exit status of the process is consulted in determining the success
358 of the action. An exit status of zero means that the action succeeded.
359 Any other exit status (or abnormal termination) means that the action
362 In order to avoid any time limitations, you might implement a process
365 The parent would return the appropriate
366 value immediately, and the child could continue on, doing whatever it
367 wanted for as long as it wanted. This approach is somewhat risky if
368 the parent is going to return an exit status of zero. If the parent is
369 going to return a non-zero exit status, then this approach can lead to
370 quicker delivery into your maildrop.
375 .ta \w'%etcdir%/ExtraBigFileName 'u
376 ^%etcdir%/mts.conf~^nmh mts configuration file
377 ^$HOME/\&.maildelivery~^The file controlling local delivery
378 ^%etcdir%/maildelivery~^Rather than the standard file
379 ^%mailspool%/$USER~^The default maildrop
383 rcvdist(1), rcvpack(1), rcvstore(1), rcvtty(1), mh\-format(5)
388 .RB ` \-nosuppressdup '
389 .RB ` \-maildelivery "' defaults to $HOME/\&.maildelivery"
390 .RB ` \-mailbox "' deaults to %mailspool%/$USER"
391 .RB ` \-file "' defaults to stdin"
392 .RB ` \-user "' defaults to the current user"
400 was originally designed to be backward-compatible with
406 .RI \*(lq \&.maildelivery \*(rq
407 file syntax is somewhat limited. But
409 has been modified and extended, so that is it no longer compatible with
412 In addition to an exit status of zero, the
418 (9) mean that the message has been fully delivered.
419 Any other non-zero exit status, including abnormal termination, is
425 \*(lquse an alternate route\*(rq (deliver the message to the maildrop).
428 Only two return codes are meaningful, others should be.
431 was originally designed to be backwards-compatible with the
433 functionality provided by