Configuring POP3 IMAP Clients
POP3 and IMAP and SMTP Authentication
Virtualmin configures the Dovecot POP3 and IMAP server for usage with all common mail clients, and Cyrus saslauthd for SMTP authentication on outgoing mail.
POP3/IMAP Username
You can always find the username for a user by looking on the Edit Mail and FTP Users page for the virtual server in which the user exists. It will be displayed in the IMAP/FTP login field. With the exception of users with @ in them, the username will be the same for all services (mail, ssh, FTP, Usermin, etc.).
Username Conventions
Virtualmin, by default, creates system login names by combining the username and the first part of the domain name, separated by a configurable separator (“.” by default). Thus, a user named joe within the virtualmin.com domain would use the login name joe.virtualmin.
This is, of course, completely configurable. To choose the username format used, browse to System Settings:Server Templates and select the Mail for domain section, and locate the Format for usernames that include domain field at the bottom of the page.
user@domain.tld Style Usernames
Virtualmin also supports user@domain.tld style usernames, though there are some caveats in this configuration. Specifically, Postfix does not support delivery to users with @ in them, and so Virtualmin creates two users (one that Postfix will deliver to, and one with @).
In order for SMTP authentication to work with users in this format, saslauthd also needs to be configured to include domain information.
On Red Hat, Fedora, and CentOS systems, edit /etc/sysconfig/saslauthd and add "-r" to the FLAGS= line, save it and restart the saslauthd service.
On Debian and Ubuntu, edit /etc/defaults/saslauthd and add the "-r" flag to the PARAMS= line, save it, and restart the saslauthd service.
Thunderbird
Open the Account Settings dialog. Click the Add Account button in the lower right corner of the window. Select Email account and click Next.
Fill in your name and the email address for this account.
Select POP or IMAP, fill in the hostname of the Virtualmin server in the Incoming Server, and then click Next.
On the next page, fill in the username. Click Next.
Give the account a name (the default will be the email address associated with the account).
Finding out PHP version
Different versions of PHP may have different default settings, and in the case of newer versions might have new functions. If you can’t get something to work, and think it might be because you have the wrong version of PHP there is a simple way to check. Simply running the phpinfo () function will not only tell you your PHP version but an abundance of information about all your PHP settings. Here is an example:
<?php phpinfo() ?>
Just put that single line of code in a PHP file, and run it on your server. That’s it! By running the file you should have all of the PHP information you need.
Install PECL APC Cache
The Alternative PHP Cache (APC) is an op-code pre-compiler and a cache system that can boost the performance of a PHP application up to 10 times. Op-code caches are very effective for a Drupal website, since Drupal deals with large number of source files and time spent in parsing them significantly affects performance. However, if you don’t have XAMPP and need to install it on CentOS, you can follow this to get around some of the problems that happen with the default server settings. h2. Install Pre-reqs Using yum install the required prerequisites.
sudo yum install php-devel php-pear httpd-develInstall APC
Use the command
sudo pecl install apc at this point you’ll likely see the error
Fatal error: Allowed memory size of 8388608 bytes exhausted (tried to allocate 92160 bytes) in /usr/share/pear/PEAR/PackageFile/v2/Validator.php on line 1831 Apparantly, the PECL/PEAR scripts do not use the settings from /etc/php.ini so you need to update PEAR’s memory settings to give is some more breathing room. Edit the file /usr/share/pear/pearcmd.php and add the following at the beginning:
@ini_set('memory_limit', '16M');Configure/Restart
Now configure PHP to use the new extension. Create the file /etc/php.d/apc.ini and in that file put:
extension=apc.soNow restart apache
sudo /etc/init.d/httpd gracefulMaintenance
In the future, if new versions of APC are released, you can easily upgrade them using
sudo pecl upgrade apcYum Updates
Task: List all installed packages
List all installed packages, enter:
# rpm -qa
# yum list installed
Find out if httpd package installed or not, enter:
# rpm -qa | grep httpd*
# yum list installed httpd
Task: Check for and update specified packages
# yum update {package-name-1}
Task: Install the specified packages [ RPM(s) ]
Install package called httpd:
# yum install {package-name-1} {package-name-2}
# yum install httpd
Task: Remove / Uninstall the specified packages [ RPM(s) ]
Remove package called httpd, enter:
# yum remove {package-name-1} {package-name-2}
# yum remove httpd
Task: Display the list of available packages
# yum list all
Task: Display list of group software
Type the following command:
# yum grouplist
How to change a Linux password
A normal user may only change the password for his/her own account, the super user may change the password for any account. The administrator of a group may change the password for the group. passwd also changes account information, such as the full name of the user, user’s login shell, or password expiry date and interval.
Type passwd command as follows:
$ passwd
The user is first prompted for his/her old password, if one is present. This password is then encrypted and compared against the stored password. The user has only one chance to enter the correct password. The super user is permitted to bypass this step so that forgotten passwords may be changed.
A new password is tested for complexity. As a general guideline, passwords should consist of 6 to 8 characters including one or more from each of following sets:
– Lower case alphabetics
– Upper case alphabetics
– Digits 0 thru 9
– Punctuation marks
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