26.16 Procmail Recipes
REVIEW
We now start specifying recipes to handle email. A recipe generally contains a pattern to identify the email messages to which the actions of the recipe are to be applied. Generally, the first recipe that matches an email will process that email and then terminate the procmail processing of that message.
26.16.0.0.1 Carbon Copy all Email
For the especially cautious, or for when setting up procmail and testing it, you may want to keep a copy of every email that comes through. The first recipe might then be:
All recipes are introduced with the :0. This can be followed
by flags to control how the recipe works. The c flag above
indicates that the email message is to be processed further by this
specific recipe, but also a copy is to be pushed through to the remainder of
the recipes within the .procmailrc file. The final :
indicates that while procmail is processing the email
message with this recipe, the recipe should be locked (so that no
other procmail can write to the specified file at the same
time).
After introducing the recipe with the :0 line, the next line
in the above example is the action to be performed. In this case a
file name is specified, beginning with a full stop and calling on the
operating system to provide a current year and month string
(e.g. 2006.01).
26.16.0.0.2 Forwarding Email
We can specify exactly which emails we wish a recipe to apply to. We do this for a recipe which will forward email on to another user, as well as keeping a copy for ourselves:
Lines beginning with * allow us to identify email messages to
which the recipe should apply. This example forwards any email from
particular users (any email from anyone with an email address that has
the string abc.com in it), onto another user
(abcuser@togaware.com). You can have a comma separated list
of email addresses on to which the email should be forwarded.
With this recipe the recipe introduction uses the c flag to
pass the email message on to following recipes as a carbon copy. Also,
there is no trailing colon, so we are not requesting a lockfile for
this recipe—in this case we don’t need to use a lockfile because two
instances of procmail will not interfere with each other
when the action is to send the email on to someone else.
26.16.0.0.3 Other Examples
A sample .procmailrc:
# DEBIAN
:0:
* ^Resent-Sender.*debian-devel-request@lists.debian.org
lists/debian-devel
:0:
* ^Resent-Sender.*debian-user-request@lists.debian.org
lists/debian-userThe :0 begins a recipe. The following : ensures the mail
file is locked. A line beginning with * begins a condition. You
can have multiple conditions within a recipe. The condition
^Resent-Sender.*debian-devel-request@lists.debian.org
captures email sent to the debian-devel mailing list. This matches
messages that include
Resent-Sender: debian-devel-request@lists.debian.org
in their header. The final line of a recipe is the mailbox into
which procmail will send the mail.
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