mailexec - run program on messages in mbox file or maildir
mailexec [-nvFR] mailbox program
mailexec runs a program over every message in mailbox
, which must be an
mbox-format mail file or maildir directory. For each message encountered,
mailexec executes program
with the specified arguments, supplying the
message as standard input. mailexec synthesizes a "From "
line and a "Return-Path:" header field for each message if the
message does not already contain one. (This behavior can be modified by the
flags, described below.)
When parsing mbox format files, mailexec unescapes "From " lines. If a
line begins with one or more ">" characters followed by
"From ", mailexec deletes one of the ">" characters. If
you do not want this unescaping behavior, see the formail
which has a -s
flag that performs a similar function to mailexec.
- When processing a maildir, causes mailexec to look exclusively at
"new" messages that have not yet been moved to the cur
- Turns on verbose mode. If mailbox is a maildir, mailexec prints out
the name of each file it processes inside the maildir. If mailbox
is an mbox format file, mailexec prints the message-id of each message it
processes (as long as messages have a message-id header).
- Suppresses printing of the initial "From " line at the beginning
of each message.
- Suppresses printing of initial "Return-Path:" lines.
To get the same behavior as the Unix from
(1) command on a mail directory
, you can run either of the following two commands:
mailexec -n dir head -1
mailexec -n dir sed -ne 1p
To convert an mbox-format file mbox
into a maildir directory dir
you can run:
mailexec mbox deliver dir/
Conversely, to convert maildir dir
into an mbox-format file mbox
mailexec dir deliver mbox
To train the spamassassin filter on a mail folder called spam
unwanted messages, run:
mailexec spam sa-learn --spam
Note that this works whether spam
is an mbox format file or a maildir
If you have an old mbox file or maildir directory box
and wish to
"import" the old mail into your web mail account, say
, you can run:
mailexec -F box sendmail firstname.lastname@example.org
Note again that this works whether box
is an mbox format file or a
The Mail Avenger home page: <http://www.mailavenger.org/>.
When reading from a maildir and synthesizing a "From " line, mailexec
guesses the delivery date of the message based on the name of the file, which
works in practice but could be considered dangerous since file names in
maildirs are supposed to be opaque. Thus, while generally mailexec places
sensible dates in "From " lines and processes maildir messages in
order of delivery, it might be unwise to rely on this behavior.
mailexec generates the time for the "From " line in the local time
zone, as is customary on Unix. This could lead to loss of information when
transferring mailboxes across time zones or combining mailboxes created in
different timezones. Moreover, this practice is incompatible with qmail, which
uses GMT in the "From " line.
mailexec expects that if there is a "Return-Path:" header field, it
will be the first header field in the message (possibly after the initial
"From " line, which is not itself a header field).
There are many different variants of the mbox message format. mailexec expects
the "mboxrd" variant, in which each message is delimited by a
"From " line at the beginning and a blank line at the end, and every
line beginning with either "From " or one or more ">"
characters followed by "From " is escaped by adding another
">" character. In particular, this means mailexec will
incorrectly parse System V "mboxcl2" files, which use
"Content-Length:" header fields to determine message boundaries
rather than "From " lines.
mailexec attempts to lock mbox format files, but will execute anyway even if it
cannot obtain the lock. This allows it to work on read-only files, but if you
are highly unlucky could result in the last message being truncated.
There is no locking for maildir files. If a maildir is modified while mailexec
is running over it, mailexec could miss messages. If you are concurrently
manipulating the maildir with a mail reader, maildir could even miss old
messages that just happen to have been moved from the new
directory. mailexec will issue a warning if it fails to open a file
that it had previously seen when scanning the directory.