Courier IMAPd and Mail.app warnings

After installing an ISPConfig deployment, everything seemed to work properly, but every now-and-then I got this weird error that there was something wrong with the mail server configuration. The Apple Mail.app showed a exclamation mark with the following message:

The server returned the error: The attempt to read data from the server server.domain.ext failed.

Some research showed that the Apple mail clients tend to open several connections for IMAP, and the default setting of the Courier IMAPd server is to allow (only) 4 connections from the same IP address.

Modifying the Courier config file (/usr/lib/courier-imap/etc/imapd) and allowing e.g. 20 connections from 1 IP address solved this problem.

<ORIGINAL CONFIG>
##NAME: MAXPERIP:0
#
#  Maximum number of connections to accept from the same IP address

MAXPERIP=4

<MODIFIED CONFIG>
##NAME: MAXPERIP:0
#
#  Maximum number of connections to accept from the same IP address

MAXPERIP=20

 If your company / household holds several imap mail clients you may need to increase the counter even more (65536 is the maximum amount of connections for ANY IP address).

If you have SSL enabled on the Courier IMAPd server you also need to add the MAXPERIP variable to the imap-ssl config file (/usr/lib/courier-imap/etc/imapd-ssl).

Finally, you need to restart the Courier IMAPd services (/etc/init.d/courier-imap restart)

Changing SSL Certificates in a ISPConfig v3 Configuration

When you install a Perfect Server based on Centos and ISPConfig v3.x, the system / 'installer' creates for the components self-signed certificates. All these certificates will generate different warnings in your browser, mail clients etc. So time to eliminate those warnings.

First I needed to find out where all those certificates are located, and what there formats are. In my case, there are three services that use SSL/TLS in some form;

1. Postfix SMTP service
2. Courier IMAP service
3. http / Apache2 webservice

Checking the configuration files will reveal their locations.

Click to read more ...

Getting ISPConfig to Work on Centos

This is not a manual describing the installation (pre-requisites) of ISPConfig software on a Centos platform. An excellent manual can be found online. It's just that I ran into a problem when I tried to connect an e-mail client to the (IMAP) mailserver (controled by ISPConfig). All the appropriate ports / listeners were up and running, so it had to be a configuration issue.

Googling around didn't solve my problem. My collegue, Xander (@xmoments / xmoments.nl), cam eto the rescue with the solution;

yum install cyrus-sasl-plain-2.1.23-13.el6.x86_64

Software that handles cleartext passwords between mail processes. After the installation, the mail went flying across the Interwebs.

Adobe Coldfusion 9 on CentOS 5.4 (x64)

Updated on Monday, April 5, 2010 at 18:53 by Willem

A while back I figured out how to install Adobe (could have been Macromedia back then) Coldfusion MX on an Ubuntu linux server. This config still runs as it should, but in the mean time several things have changed in the world of software. I've been leaning towards Centos 5.4, and Adobe released Coldfusion 9 somewhere in 2009. These two 'events' made me decide to combine the two.

Before I continue, I must warn you that the Coldfusion installer is still broken..... So there's some manipulation of code involved.

Since the new 'server' is going to run in a virtual environment I started in a VMWare Workstation. This way I could make snapshots of my progress. This made it easier to start from scratch. The problem with Linux and me is that I tend to reinstall the OS when things go haywire. So VMWare is a safe way out in this case.

Click to read more ...

Why Linux Won't Work

.... for me at this moment (and probably for most others).

I'm still in the fase of migrating my Windows server to a more 'reliable' Operating System. The new server should cover the following basic functionalities:

• Filesharing (either via Samba or NFS)
• Webserver with PHP and Coldfusion
• SSH server
• RADIUS Server
• Central user database (e.g. an LDAP server)
• a NZB downloader of some sort
• etc.

Up till now I've tried several Linux distros (Ubuntu 7, Ubuntu 8, and CentOS 5), and none of them are that easy to configure.

It seems that NFS isn't that easy to configure, since Apple OSX requires some special features (standards anyone??). Especially when you want some sort of user authentication. Just do a search on Linux, NFS and Apple OSX.

So after NFS didn't really work, I tried SMB for filesharing. While CentOS has some GUI to configure the shares, it lacks the interface of permissions for users...
You create users within the Linux environment, and if you wanna connect to a Samba share you need to configure additional users (in a different userdatabase).
This can be done by synchronization, but you need to do some scripting etc.

So far I've managed to install a working SSH server (with x509 authentication) and a Webserver.

When I compare this with Windows.... Well, there's no real comparison. Windows has a real central user database (not talking about the Active Directory here, but the local user database). And every service I need can talk to this database, and every service recognizes this database. No need to start 'hacking' some configuration files to make it work.

Well, as long as there's no new (read:better) interface of configuring those services and combining them with a shared user database ....

LINUX >> /dev/null

Recommendations can be left in the comments (if there are any)......