Nasim Mansurov

11) Installing and configuring VMailMgr
To install VMailMgr, we need to run configure and make just like we do on any other source distributions:

# cd /usr/local/src
# tar zxf vmailmgr-0.97.tar.gz
# cd vmailmgr-0.97
# ./configure
# make
# make install
# cd ..
# tar zxf vmailmgr-tools-0.2.tar.gz
# cd vmailmgr-tools-0.2
# make
# ./installer

If you receive an error for vmailmgr-tools compilation, edit vcheckquota.c, go to line 36 and simply put the sentence “Warning: the soft…blah blah” in one line. Type make again and the problem should go away. Let’s configure VMailMgr to work with our domain.

# groupadd email
# mkdir /home/email
# chmod 755 /home/email

Apart from the main installation, we’ll have to configure VMailMgr as well. This step is required for controlling user quotas, auto-responder and some
other things.

# mkdir /etc/vmailmgr
# chmod 755 /etc/vmailmgr
# cd /etc/vmailmgr
# ln -s /etc/vmailmgr /usr/local/etc/vmailmgr
# echo ./Maildir/ > default-maildir
# echo maildir > maildir-arg-str
# echo passwd > password-file
# echo /tmp/.vmailmgrd > socket-file
# echo users > user-dir

Create a file called vdeliver-predeliver (vi vdeliver-predeliver), then copy-paste the following:

#!/bin/sh
/usr/local/bin/vcheckquota

Then, change permissions of the files in the folder:

# chmod 755 /etc/vmailmgr/*

The directory /etc/vmailmgr is created for vmailmgr configuration files. The echo commands given above control the way vmailmgr will be handling directories and mail processing. Basically, we are telling vmailmgr that the password file for keeping users’ passwords will be “passwd” and the directory that will contain individual user accounts will be “users”. The “vdeliver-predeliver” lines will launch “vcheckquota”, which will check a user’s quota limits before delivering a message. You can change the above settings to fit your needs, but I would recommend using the default settings provided in this guide.

Now we need to create a set of scripts that should help us out a lot in adding and removing virtual domains. Download the file add_virt from this server and place it in /usr/local/bin.

The script is pretty simple. The first line sets a variable DGID (group ID) to “email”, which is used while executing useradd to add a virtual domain to the system. The second line sets DHOME to “/home/email”, which will be the base directory for all virtual domains you’ll be creating in the future. QHOME is the directory where qmail is installed. The next four lines check if the user is root (remember, only root account will be able to execute this script). If nothing is given in command line, the script will print “Usage: add_virt newdomain.com”, for those who don’t know or forgot the script usage. Next, the script checks if the virtual domain already exists, by going through the system /etc/passwd file. Don’t worry, the scipt will not screw up or damage your passwd file. Vmailmgr uses *nix authentication to verify virtual domains. However, it does not necessarily mean that you are leaving security holes. After creating the first test user, I will show you how to disable shell access to all created virtual domains for security purposes. When all the checks are completed successfully, the script will attempt to create the virtual domain you specified in command line. It will first launch useradd and add the domain. Then, it will prompt you to change the password for the created virtual domain. Next, the script will add the domain to /var/qmail/control/virtualdomains and /var/qmail/control/rcpthosts. The next line executes vsetup, which takes care of setting up a virtual domain for its first use. And finally, the last three commands will restart qmail, so that the new settings take effect. If everything went without a glitch, the script will print out “All done! Domain newdomain.com created.”

Now, get the second file remove_virt and also place it in /usr/local/bin.

This script does the reverse of add_virt - i.e. it will remove the specified virtual domain from the system. Again, QHOME is where your qmail is installed. Another check for root user is run to prevent regular users from attempting to execute this script. If nothing is specified in command line, the script prints “Usage: remove_virt domain.com”. Next, a quick check that tests the existence of the virtual domain in /etc/passwd is run. If the domain is found, the root account will be asked to confirm the deletion of the specified domain and all of its users. If “y” is received, the account is deleted from the system via userdel. If nothing or “n” is received, the script exits with “Aborted.” message. Once userdel removes the system account, the script changes directory to /var/qmail/control and removes the deleted virtual domain from “virtualdomains” and “rcpthosts” files (the grep and mv lines). The last three commands restart qmail, for changes to take effect. If everything went smoothly, the script prints out “All done! Domain deleteddomain.com deleted.”

Good, now we need to chmod those scripts, so that they are be executable. Plus, let’s test those scripts by creating a virtual domain (yourserver.com):

# chmod 755 /usr/local/bin/add_virt
# chmod 755 /usr/local/bin/remove_virt
# add_virt yourserver.com
Base Username [yourserver_com]:
Creating new domain ‘yourdomain.com’.
Domain base user created in /home/email/yourdomain.com.
Please provide domain password for VmailMgr.

Changing password for user yourdomain_com.
New password:
Retype new password:
passwd: all authentication tokens updated successfully.
Adding domain to control/virtualdomains…done
Adding records to control/rcpthosts…done
Setting up the domain dir for vmailmgr…
vsetup: created users directory.
vsetup: wrote ‘.qmail-default’ file.
vsetup: added alias ‘mailer-daemon’
vsetup: added alias ‘postmaster’
vsetup: added alias ‘root’
…done
Restarting Qmail…
All done! Domain yourdomain.com created.

After your type add_virt yourserver.com you’ll be asked for a password. Type the domain password and remember it - we’ll need it for domain administration later on. The script output will be similar to what you see above. If you get an error saying bash: /root/.bashrc: Permission denied in the middle of the script, just ignore it.

Let’s now create a test user at our domain. This user will be created solely for testing purposes. We’ll delete it after we are sure that everything is working properly.

# su - yourserver_com
# vadduser test
Enter the user’s new password:
Please type it again for verification:
vadduser: user ‘test’ successfully added

The account is created successfully. Remember or write down the password you specified - we’ll need the password later for testing our mail server. Once you are done adding the user, type “exit” to return to superuser shell.

Now we need to disable the created virtual domains’ shell access for security purposes. Launch your favorite editor and open /etc/passwd. Find the line with your created virtual domain. It will look something like this: yourserver_com:x:5007:5002::/home/email/yourserver.com:/bin/bash. Replace “/bin/bash” with either “/sbin/nologin” or “/bin/false”. This makes sure that even if someone steals your domain password, he/she will not be able to use the shell.

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Posted by MegaZ on 12/20/2002.