Re: postfix mail filtering

[Dan Ritter <dsr@randomstring.org>]

On Wed, Aug 31, 2016 at 01:21:13PM +0100, Tony van der Hoff wrote:
> Hi list,
> 
> I'm running postfix under Wheezy on my VPS, using a more or less
> out-of-the-box configuration. My users access their mail via IMAP.
> 
> I subscribe to a number of mail lists, such as this one. I currently use
> Thunderbird's filtering capability to sort mail into a number of
> subdirectories within my inbox, which works fine, but requires me to set up
> all my workstayions (laptop, home, work) with the same filters. I have now
> acquired an Android smartphone, which has no filtering capability. In any
> case, keeping a number of workstations in sync is a pain.
> 
> So, I'd like to perform the filtering on the server (for my user initially,
> then perhaps for others). My extensive googling reveals that there are many
> tutorials for filtering spam, but that's not really my problem.
> 
> I can't find any tutorials on how to set up filters based on, say subject:,
> from:, or to: fields, but feel certain such must exist.
> Can any kind person direct me to a suitable tutorial, please?

You can use:

- sieve, a language for controlling filtering on IMAP servers.
  Supported by Thunderbird but not very much else.

- procmail, a language for filtering on delivery (postfix will
  call it) -- widely known, but arcane syntax and requires shell 
  access to edit or place the ~/.procmailrc

- maildrop, aka mailfilter, a language for filtering on delivery
  (postfix will call it, too) -- less widely known, but has
  syntax that is much more readable than procmail. Requires
  shell access to place a ~/.mailfilter file.

All of these have Debian packages.

-dsr-