Provided by: maildrop_2.9.3-2build2_amd64 
NAME
maildropex - maildrop filtering language examples
SYNOPSIS
$HOME/.mailfilter, $HOME/.mailfilters/*
DESCRIPTION
If $HOME/.mailfilter exists, filtering instructions in this file will be carried out prior
to delivering the message. The filtering instructions may instruct maildrop to discard the
message, save the message in a different mailbox, or forward the message to another
address. If $HOME/.mailfilter does not exist, or does not provide explicit delivery
instructions, maildrop delivers the message to the user's system mailbox.
The files in $HOME/.mailfilters are used when maildrop is invoked in embedded mode.
EXAMPLES
Take all mail that's sent to the 'auto' mailing list, and save it in Mail/auto. The 'auto'
mailing list software adds a "Delivered-To: auto@domain.com" header to all messages:
if (/^Delivered-To: *auto@domain\.com$/)
to Mail/auto
After the to command delivers the message, maildrop automatically stops filtering and
terminates without executing the subsequent instructions in the filter file.
Take all mail from <boss@domain.com> about the current project status, save it in
Mail/project, then forward a copy to John:
if (/^From: *boss@domain\.com/ \
&& /^Subject:.*[:wbreak:]project status[:wbreak:]/)
{
cc "!john"
to Mail/project
}
Note that it is necessary to use a backslash in order to continue the if statement on the
next line.
Keep copies of the last 50 messages that you received in the maildir directory 'backup'.
NOTE: 'backup' must be a maildir directory, not a mailbox. You can create a maildir using
the maildirmake command.
cc backup
`cd backup/new && rm -f dummy \`ls -t | sed -e 1,50d\``
Put this at the beginning of your filter file, before any other filtering instructions.
This is a good idea to have when you are learning maildrop. If you make a mistake and
accidentally delete a message, you can recover it from the backup/new subdirectory.
Save messages that are at least 100 lines long (approximately) into Mail/IN.Large::
if ( $LINES > 100 )
to Mail/IN.Large
Send messages from the auto mailing list to the program 'archive', using a lock file to
make sure that only one instance of the archive program will be running at the same time:
if (/^Delivered-To: *auto@domain\.com$/)
dotlock "auto.lock" {
to "|archive"
}
Check if the Message-ID: header in the message is identical to the same header that was
recently seen. Discard the message if it is, otherwise continue to filter the message:
`reformail -D 8000 duplicate.cache`
if ( $RETURNCODE == 0 )
exit
The reformail[1] command maintains a list of recently seen Message-IDs in the file
duplicate.cache.
Note
Unlike a similar feature in the formail command, reformail[1] takes care of locking
the file, so it's not necessary to implement your own locking mechanism for this
option.
Here's a more complicated example. This fragment is intended to go right after the message
has been filtered according to your regular rules, and just before the message should be
saved in your mailbox:
cc $DEFAULT
xfilter "reformail -r -t"
/^To:.*/
getaddr($MATCH) =~ /^.*/;
MATCH=tolower($MATCH)
flock "vacation.lock" {
`fgrep -iqx "$MATCH" vacation.lst 2>/dev/null || { \
echo "$MATCH" >>vacation.lst ; \
exit 1 ; \
} `
}
if ( $RETURNCODE == 0 )
exit
to "| ( cat - ; echo ''; cat vacation.msg) | $SENDMAIL"
This code maintains a list of everyone who sent you mail in the file called vacation.lst.
When a message is received from anyone that is not already on the list, the address is
added to the list, and the contents of the file vacation.msg are mailed back to the
sender. This is intended to reply notify people that you will not be answering mail for a
short period of time.
The first statement saves the original message in your regular mailbox. Then, xfilter[2]
is used to generate an autoreply header to the sender. The To: header in the autoreply -
which was the sender of the original message - is extracted, and the getaddr[3] function
is used to strip the person's name, leaving the address only. The file vacation.lst is
checked, using a lock file to guarantee atomic access and update (overkill, probably).
Note that the backslashes are required.
If the address is already in the file, maildrop exits, otherwise the contents of
vacation.msg are appended to the autoreply header, and mailed out.
Note
An easier to make a vacation script is with mailbot(1)[4].
Here's a version of the vacation script that uses a GDBM database file instead. The
difference between this script and the previous script is that the previous script will
send a vacation message to a given E-mail address only once. The following script will
store the time that the vacation message was sent in the GDBM file. If it's been at least
a week since the vacation message has been sent to the given address, another vacation
message will be sent.
Even though a GDBM database file is used, locking is still necessary because the GDBM
library does not allow more than one process to open the same database file for writing:
cc $DEFAULT
xfilter "reformail -r -t"
/^To:.*/
getaddr($MATCH) =~ /^.*/;
MATCH=tolower($MATCH)
flock "vacation.lock" {
current_time=time;
if (gdbmopen("vacation.dat", "C") == 0)
{
if ( (prev_time=gdbmfetch($MATCH)) ne "" && \
$prev_time >= $current_time - 60 * 60 * 24 * 7)
{
exit
}
gdbmstore($MATCH, $current_time)
gdbmclose
}
}
to "| ( cat - ; echo ''; cat vacation.msg) | $SENDMAIL"
This script requires that maildrop must be compiled with GDBM support enabled, which is
done by default if GDBM libraries are present.
After you return from vacation, you can use a simple Perl script to obtain a list of
everyone who sent you mail (of course, that can also be determined by examining your
mailbox).
SEE ALSO
maildrop(1)[5], maildropfilter(7)[6], reformail(1)[1], mailbot(1)[4], egrep(1), grep(1),
sendmail(8).
AUTHOR
Sam Varshavchik
Author
NOTES
1. reformail
http://www.courier-mta.org/maildrop/reformail.html
2. xfilter
http://www.courier-mta.org/maildrop/maildropfilter.html#xfilter
3. getaddr
http://www.courier-mta.org/maildrop/maildropfilter.html#getaddr
4. mailbot(1)
http://www.courier-mta.org/maildrop/mailbot.html
5. maildrop(1)
http://www.courier-mta.org/maildrop/maildrop.html
6. maildropfilter(7)
http://www.courier-mta.org/maildrop/maildropfilter.html