Using Kerio Connect Mailserver for a mailing list server only


Kerio Connect has a nice built in mailing list capability. You can read more about its features at my Kerio Mail Server Mailing Lists, but here I want to talk about a less typical usage where a base Connect server is used only for this function and for no other.

For example, let's say you are using Gmail or some other cloud service for your mail domain. That service does not offer a mailing list function (note that mailing to groups is most definitely NOT the same as a mailing list - read that other article if you don't understand that), but you'd like to be able to do that and you do NOT want to use a separate email domain for that purpose. With some limitations, a base 5 user version of Kerio Connect can handle this for you.

You set up Kerio with an administrator account, but you don't need to add any other users. You tell the server that it is "", but it doesn't matter whether there is any access FROM the Internet to it. All this server needs is the ability to send mail OUT, and of course that can be through a relay server if necessary.

Confused? Contact me

This can be very confusing if you are not familiar with how mail and mailing lists actually works - I can help you set this up and get it running. Contact me by email or phone to get started.

An Example

A local Connect server that thinks it is

Note that this server thinks it is responsible for "". It isn't, but as no MX DNS record will ever send any email to it, that doesn't matter. It actually cannot receive email: my router doesn't pass SMTP connections to any internal machine at all - my real mail server is hosted elsewhere.

This bit of fiction means that mail headers it sends will identify as To help it maintain this fiction, I used my real server as its relay server:

setting relay options

That's not strictly necessary, but it can assist delivery as the real uses an SPF record (see Kerio Spam Control: Caller-ID and SPF). I used my gmail address as a member of the mailing list; this is how gmail sees the headers:

Received: by with SMTP id z3csp96608lbq;
        Sat, 28 Jul 2012 12:16:06 -0700 (PDT)
Received: by with SMTP id we5mr7547554igb.62.1343502966015;
        Sat, 28 Jul 2012 12:16:06 -0700 (PDT)
Return-Path: <>
Received: from ( [])
        by with ESMTPS id fn10si7448576icc.32.2012.
        (version=TLSv1/SSLv3 cipher=OTHER);
        Sat, 28 Jul 2012 12:16:05 -0700 (PDT)
Received-SPF: pass ( domain of designates as permitted
sender) client-ip=;
Authentication-Results:; spf=pass (
domain of designates
as permitted sender)
Received: from localhost ([])
	(using TLSv1/SSLv3 with cipher AES256-SHA (256 bits))
	Sat, 28 Jul 2012 15:16:02 -0400
X-Footer: YXBsYXdyZW5jZS5jb20=
Date: Sat, 28 Jul 2012 15:15:57 -0400
Subject: test to foolist
X-Mailer: Kerio Connect 7.5.0 beta 2 WebMail 2
X-User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_8_0)
	AppleWebKit/536.11 (KHTML, like Gecko) Chrome/20.0.1132.57 Safari/536.11
Message-ID: <-821805965--1323544576@anthonys-imac.local>
X-Priority: 3
MIME-Version: 1.0
Content-Type: multipart/alternative; boundary="=-fBhRMLTYbwVXsN306XgT"
Sender: <>
List: <>
List-Help: <>
List-Post: <>
List-Subscribe: <>
List-Owner: <>
List-Id: <>
List-Unsubscribe: <>
Errors-to: <>
X-BeenThere: <>
Precedence: list


Thare are some limitations to this. If I wanted to include people at in my mail list, I'd need to set up domain forwarding:

Forward unknown users

I can't do that easily here because Verizon blocks outgoing port 25. I could select another port, but of course I'd have to configure my real server to run SMTP on that port also.

Another limitation is that no one can send mail to this server, so it cannot handle email subscriptions and unsubscriptions - you'd have to do that manually. People CAN reply, of course: the email will go to the real server.

Inexpensive mailing lists

You can set up as many mailing lists as you like - mailing lists do not count against user licenses. This means you only need a base, 5 user Kerio Connect license, which is very inexpensive.

Each mailing list can contain users you import manually or import from a csv file. Those names don't count against licenses either, of course.

You can also put a server like this out on the internet with its own domain and MX records pointing right at it. In that case, it can receive mail so all of the subscription features become possible.

Got something to add? Send me email.

(OLDER) <- More Stuff -> (NEWER)    (NEWEST)   

Printer Friendly Version

-> -> Using Kerio Connect Mailserver for a mailing list server only

Increase ad revenue 50-250% with Ezoic

More Articles by

Find me on Google+

© Anthony Lawrence

Kerio Connect Mailserver

Kerio Samepage

Kerio Control Firewall

Have you tried Searching this site?

Unix/Linux/Mac OS X support by phone, email or on-site: Support Rates

This is a Unix/Linux resource website. It contains technical articles about Unix, Linux and general computing related subjects, opinion, news, help files, how-to's, tutorials and more.

Contact us