April 2024 - This site, and Kamaelia are being updated. There is significant work needed, and PRs are welcome.

Kamaelia: Grey

What is Kamaelia: Grey ?

It's a greylisting SMTP proxy. It doesn't replace your existing mail server, but does sit between your mail server and the outside world.

How do I install it?

After unpacking, as root, type:

Under linux you then type:

The code was developed under linux, but is currently acting as a workhorse under Mac OS X. As a result a startup script for Mac OS X is also included - take a look in the setup.py file to see what you need to edit.

How do I configure it?

Copy the default config file - installed to /etc/greylist.conf.dist to a localised version - ie /etc/greylist.conf

You then edit the freshly copied config file. The config options are documented in the config file.

How does it work then?

Suppose your existing mailserver:

You change your mailserver to listen on some other port instead. eg 8025 You then configure Kamaelia:Grey to listen on port 25 instead, on that host.

You also configure Kamaelia:Grey to forward to your mail server

How do I configure that?

Edit /etc/greylist.conf

Change the values smtp_ip & smtp_port

eg change them to:

smtp_ip =

smtp_port = 8025

Where can I get more information?

Information will be added to this page. (maybe) Discussion and feedback should be sent to as issues on github.

What on Earth is Greylisting?

Without apologies, here's a link to a non-techie (albeit a bit silly) description of greylisting:

More detail on how Kamaelia: Grey works: (this should get consolidated onto this page)

I want to understand more?

A presentation

Kamaelia Grey from kamaelian

You may also wish to look at Kamaelia: Spam Assistant

Getting the code

NB, this is currently out of date and so commented out for now