Next step in the migration

Had some time to spare today so a bit quicker then anticipated here is step 2 in the migration from Courier to Dovecot. In this step we move away from Courier-Auth to the Dovecot built in authentication module for the Postfix SASL SMTP authentication.

Read on for more information on step 2 for the migration.

Courier to Dovecot migration

Finally I’ve started the official migration of my production server from the Courier programs to Dovecot. I’ve done it several times on a test server but that is nothing compared to doing it or real on a server where there are a lot more emails and users working on.

I already ran into some problems that I haven’t seen one any of my test runs, which shows that it was good to do this upgrade myself for real before posting the full writeup. I’m posting the migration in several independent steps which you can do at your own leisure and speed. After each step you will have a fully functioning mailserver where only a small part of the setup has been changed. In this manner everything should be manageable and hopefully will not pose to many issues.

In the first step we are going to replace the Courier IMAP server with the Dovecot IMAP server. The instructions will work for Leopard and Snow Leopard. The next step will be about replacing Courier Auth with the Dovecot Auth module.

But no time to waste, read the first step in migrating from Courier to Dovecot.

Courier IMAP updated to 4.6.0

For the people still running the Courier setup. Yes I know I still need to publish the migration scenario. The IMAP server got a small update. It is not a security fix so if you haven’t run into any problems you can skip this one.

Issues solved in this release are:

  • outbox.c (imapd_sendmsg): Renamed sendmsg() to avoid library name clash.
  • Fix typo in init file.
  • tls: change the default OpenSSL configuration to disable anonymous
    authentication ciphers.
  • DROP options for couriertcpd, set in the esmtpd configuration file: drop connections from blacklisted IP addresses, rather than accepting connections and rejecting all mail from them.

New mailserver setup with Dovecot

As promised earlier, now Dovecot 1.2.0 is released, I’m officialy launching the new mailserver setup with Postfix and Dovecot (Currently Leopard only).

This means no more Courier based products like the authentication, IMAP, POP3 and maildrop apps. Dovecto can do all that with a single installation. I’ve found out that the setup is a lot simpler with a lot fewer procedures and configuration files to maintain.

An last but not in the least, it looks like Dovecot is proving to be an even better IMAP server than Courier was. As I told you in the earlier post it’s a lot faster. While testing it myself I often saw new email appear in Mail or Thunderbird immidiate after thy were received by Dovecot.

Currently the setup only describes the basic setup of a server, I still need to add the DSpam spam-filter in the setup and integrate server based filtering of incoming emails (where we used to use maildrop for). It is all possible but I still need to find out how and document it for you. When that is done I will write the neccesary migration documents how existing users can migrate safely from Courier to Dovecot.

I will keep supporting the Courier product stack for at least a year after I finished documenting the migration instructions. So don’t worry if you don’t switch immediatly. My production servers still run Courier, I only use Dovecot on my test servers. Although there is one user who has already switched to Dovecot (We helped each other in getting this done) because of the performance problems he experienced with Courier IMAP. These problems are now gone and this is one of the reasons I want to move to Dovecot a.s.a.p.

The advise currently is if you want to setup a new server: Use the Dovecot based setup. If you already use Courier please wait untill the migration instructions are finished. If you can’t wait I will try to assist you via email as much as I can but you will be mostly on your own. It’s not that difficult but ou need to know what you are doing.

I hope you like the switch and will be happy with the improved setup. You can read all about it at the new mailserver instruction pages

Courier updates

Sam Varshavchik has been busy again checking everything against the new version of GCC and fixing a minor bug. He has done this for most of the Courier software stack. The ones that concern us are:

Courier-Auth was updated to 0.62.4

  • Various compilation fixes for gcc 4.4 and libtool 2.2

Courier-IMAP was updated to 4.5.1

  • Various compilation fixes for gcc 4.4
  • fetch.c (open_cached_fp): If the message file cannot be opened,
    create a dummy message in its place.

Courier Maildrop was updated to 2.2.0

Please do not use this version as it will not work, please download version 2.0.4. I’m not spending more time on this as of the switch to dovecot later this week.

  • GCC 4.4 fixes

Updating should be easy, just follow the install instructions as usual.

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