Sieve-Example:Move email to a suffix folder

Description

Say you have a single mailbox:

me@example.com

And you want to give out 'unique' addresses to companies so that you can control who has your address and helps you track and filter your email. You may want to give out addresses such as:

me-amazon@example.com
me-ebay@example.com

This is all possible with two things:

An alias - set on the Control Pages
A sieve filter

Alias

On the control pages, in the email setup, under aliases create an alias such as:

Alias

This sends messages addressed to me-ANYTHING@example.com to the me Mailbox

Sieve filter

Once messages are being sent to your Inbox, we create a sieve filter to automatically move messages to their folder, if it has been made. If the folder hasn't been made, then they will be put in to your Inbox as normal.

require ["fileinto","imap4flags","variables","regex","mailbox"];

## Move messages sent to an address with a suffix eg, me-amazon@example.com in to a folder called Filtered/amazon, if it exists.
if exists "X-Delivered-To" {

         if header :regex "X-Delivered-To" "-([A-z0-9]+)@" {
                set "suffix" "${1}";
                fileinto "INBOX.Filtered.${suffix}";
        } 
        stop;}

This filter uses the 'X-Delivered-To' header which is added by the A&A mail servers - even if you are BCC'd then the filtering will work. The X-Delivered-To is the 'envelope-to' header, which is the address the email was actually sent to by the sender (in lowercase).
You'll need to add this sieve filter - eg by using the (latest) Thunderbird Sieve extension, see Sieve_Server_Settings for info in the 'Creating Sieve Filters' section
This won't be able to be added via Roundcube, as you can't paste in raw sieve code there.

Variations

You can create the folders automatically if you wanted add :create, - but some mail clients won't refresh their folder list until they are restarted.

                fileinto :create "INBOX.Filtered.${suffix}";

Create the folders

The sieve filter puts email in to a folder called Filtered/XXX, and as long as XXX matches the suffix in the email address, the messages will get moved to there. So in your email program:

Create a folder called: Filtered
Create folders within Filtered for the suffix you want filtered there

Folder layout in your email client