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mailexec - run program on messages in mbox file or maildir


mailexec [-nvFR] mailbox program [arg ...]


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 -F and -R flags, described

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(1) utility,
which has a -s flag that performs a similar function to mailexec.

-n When processing a maildir, causes mailexec to look exclusively at "new" messages that
have not yet been moved to the cur directory.

-v 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).

-F Suppresses printing of the initial "From " line at the beginning of each message.

-R Suppresses printing of initial "Return-Path:" lines.


To get the same behavior as the Unix from(1) command on a mail directory dir, 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, run:

mailexec dir deliver mbox

To train the spamassassin filter on a mail folder called spam containing unwanted
messages, run:

mailexec spam sa-learn --spam

Note that this works whether spam is an mbox format file or a maildir directory.

If you have an old mbox file or maildir directory box and wish to "import" the old mail
into your web mail account, say example@gmail.com, you can run:

mailexec -F box sendmail example@gmail.com

Note again that this works whether box is an mbox format file or a maildir directory.

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