How to configure postfix to pipe all incoming email to a script?

Solution 1:

Ok, I just got this working -- though hairier than I thought it would be. I dropped the maildir_command part, and went with transport_maps. The key is to do 5 things:

1. Set up a db file to handle aliases (and add a catch-all alias)
2. Set up a db file to map the 'transport' for the domain in question to a special handler.
3. Compile the db files into berkeley db format that postfix wants.
4. Set up the handler in /etc/postfix/master.cf to pipe mail to the script.
5. Set /etc/postfix/main.cf to use the transport db for transport_maps, and the alias db for virtual_alias-maps.

(1) Create /etc/postfix/virtual_aliases to add a catch-all alias -- localuser needs to be an existing local user:

@mydomain.tld   [email protected]

(2) Create /etc/postfix/transport to add a transport mapping. "mytransportname" can be whatever you want; it's used below in master.cf:

mydomain.tld    mytransportname:

(3) Next, both transport and virtual_aliases need to be compiled into berkeley db files:

$ sudo postmap /etc/postfix/virtual_aliases
$ sudo postmap /etc/postfix/transport

(4) Add the transport to /etc/postfix/master.cf:

mytransportname   unix  -       n       n       -       -       pipe
  flags=FR user=localuser argv=/path/to/my/script.py
  ${nexthop} ${user}

(5) In /etc/postfix/main.cf:

  ...
  transport_maps = hash:/etc/postfix/transport
  virtual_alias_maps = hash:/etc/postfix/virtual_aliases

And... good to go! Sheesh.

Solution 2:

The only time I've used something like this was for a specific user's mailbox. All that was required was to alias that user's name to a pipe and a process in aliases:

pong: "| /usr/local/bin/gotit.pl"

This sent traffic destined for "[email protected]" to a perl script I wrote to process it.

gotit.pl (as an example, don't pick on me for crappy programming skillz =). It's job was to process an email I'd sent to our Exchange server (where it was auto-replied via some VB code) to verify that Exchange was processing email in a timely fashion. If not, the mail server would send out an alert email to our pagers and write a lock file so we didn't get constantly spammed.

#! /usr/bin/perl -w
use vars qw ( $mung $sent $tvalue $remainder $delta $fout );
$mung = time;
while (<STDIN>) {
    ($sent, $tvalue, $remainder ) = split /: /, $_, 3;
    $tvalue =~ s/(\D+)//g;
    chomp($tvalue);
    $delta = $mung-$tvalue;
    if ( $sent =~ "Sent" ) {
        $fout = "/var/spool/mailcheck/$tvalue";
        next unless ( -e $fout );
        open (TMP, "> $fout") or die "Couldn't open output file: $!\n";
        print TMP "Received in: $delta seconds.\n";
                close TMP;
        last;
    }
}

Solution 3:

After a lot of headaches I put together this solution based on a couple of different sources that resulted in much less effort, the critical steps were configuring virtual_alias_domains as well as virtual_alias_maps and making sure that the virtual mapping was to my-alias@localhost instead of just my-alias. In my example the command alias is to pipe the email to a website API endpoint, but it could just as easily pipe into something else.

Here are the steps you'll need to take:

• Set up your A and MX records for your domain, the A record @ pointing to the IP of the server you’re going to be receiving emails on and MX with the hostname @ and the value 10 mail.your-domain-name
• sudo apt-get install postfix
• Select "Internet Site" and enter your-domain-name (fully qualified)
• sudo vi /etc/postfix/main.cf
• Add mail.your-domain-name to the list of mydestination values
• Append

virtual_alias_domains = hash:/etc/postfix/virtual_domains
virtual_alias_maps = hash:/etc/postfix/virtual

to the end of the file

• sudo apt-get vi /etc/aliases

curl_email: "|curl --data-binary @- http://your-domain-name/email"

• sudo newaliases
• sudo apt-get vi /etc/postfix/virtual_domains

example.net   #domain
example.com   #domain
your-domain-name   #domain

(the #domain fields suppress warnings)

• sudo postmap /etc/postfix/virtual_domains
• sudo apt-get vi /etc/postfix/virtual

info@your-domain-name [email protected]
everyone@your-domain-name [email protected] [email protected]
email_processor@your-domain-name curl_email@localhost
@your-domain-name [email protected]
[email protected] [email protected]

• sudo postmap /etc/postfix/virtual
• sudo /etc/init.d/postfix reload