Out of the box, MySQL has very limited memory allocation for cache use. If you are using Atmail with MySQL in production, it is imperative you review and optimize MySQL for your hardware and memory. You can increase performance dramatically and reduce I/O usage by tweaking MySQL to use more of your system memory for the cache and buffers.

The two easy options for increasing performance for mysql are the innodb_buffer_pool_size and key_buffer_size options. Atmail uses InnoDB tables for the user authentication & log-files, and if you have a large userbase performance can be dramatically improved by increasing the innodb_buffer_pool_size. Other tables such as the UserSettings, Abook, use the MyISAM table format which uses the key_buffer_size option.

For a production machine running all the Atmail services with 2GB of RAM we'd recommend the following option:

/etc/my.cnf:

innodb_buffer_pool_size=256M
key_buffer_size=256M

If you have 4GB RAM, double the above. Once enabled reboot MySQL, and you will see via the process table the daemon will be allocated more memory.

Tune and check for your environment, and remember not to use the mysqld defaults for a production environment!

Sometimes you need to test SMTP Authentication is working on your server, and you may not have Outlook or another email client handy to test the connection.

You can verify SMTP authentication is working by using telnet and accessing the SMTP server directly. Below is a quick tutorial on how to test your server with Atmail for SMTP authentication details

1: First, make sure SMTP authentication is enabled via the Atmail Webadmin > Services > SMTP Settings > SMTP Authentication = On

2: Next, create or verify an existing username and password on the system

3: Build the Base64 username/password

SMTP AUTH LOGIN will encapsulate the username and password as a Base64 string. This is used to prevent sending the username/password plaintext via the network connection. Using Perl, you can issue the following command to encode the username and password as a base64 string, which can be sent to the SMTP server. Note the @ symbol is escaped to pass the string via Perl.
# perl -MMIME::Base64 -e 'print encode_base64("myusername\@domain.com")'

bXl1c2VybmFtZUBkb21haW4uY29t

# perl -MMIME::Base64 -e 'print encode_base64("weakpass")'
d2Vha3Bhc3M=

4: Access the local system. Commands we issue are highlighted in bold.
# telnet localhost 25
Trying 127.0.0.1...
Connected to localhost.localdomain (127.0.0.1).
Escape character is '^]'.
220 mydomain.com Welcome to the @Mail SMTP Server ( Exim )
ehlo test.com
250-mydomain.com localhost [127.0.0.1]
250-SIZE 52428800
250-PIPELINING
250-AUTH LOGIN
250-STARTTLS
250 HELP

The above command will verfiy AUTH LOGIN is enabled on the server. Next, send the following command to start the SMTP Authentication process

AUTH LOGIN
334 VXNlcm5hbWU6 ( Server returns username as a base64 string )

bXl1c2VybmFtZUBkb21haW4uY29t

334 UGFzc3dvcmQ6 ( Server returns password as a base64 string )

d2Vha3Bhc3M=

235 Authentication succeeded
Congratulations, SMTP authentication is now enabled and confirmed working on your server. Note you must send the Base64 string of the username and password as two commands.

To make Atmail detect the hostname of your Atmail URL, and make it automatically detect the domain name for the login page, do the following:

- open up /usr/local/atmail/webmail/application/modules/mail/views/scripts/auth
index.phtml

- find this line block:

$("#loginPage").bind('submit', function() {
email = $("#email").val();
//alert(email);
emailArgs = email.split('@');
//alert(emailArgs[0] + ":" + emailArgs[1]);
$("input[name=emailName]").val(emailArgs[0]);
$("input[name=emailDomain]").val(emailArgs[1]);

Change this to:

$("#loginPage").bind('submit', function() {
email = $("#emailName").val() + "@" + $("#emailDomain").val();
emailArgs = email.split('@');
$("input[name=emailName]").val(emailArgs[0]);
$("input[name=emailDomain]").val(emailArgs[1]);

Then, find:

RememberMe();

Below this, add:
emailDom = window.location.host.substring(8);
$("#emailDomain").attr('value', emailDom);

Note the number "8". This assumes that you use webmail.domain.com for your Atmail vhost. If you are using another Alias like mail.domain.com, the number will change from the number of the letters in the Alias plus one - making it:

emailDom = window.location.host.substring(5);

Then, find:

<tr>
<td>
<label class="user"><?php print $this->translate('Email') ?>:</label> <input id="email" class="input-email" type="text" name="email" tabindex="1" />
</td>
</tr>

Change to:

<tr>
<td>
<label class="user"><?php print $this->translate('Email') ?>:</label> <input id="emailName" class="input-email" type="text" name="emailName" tabindex="1" />
</td>
</tr>
<tr>
<td>
<label class="user"><?php print $this->translate('Domain') ?>:</label> <input id="emailDomain" class="input-email" type="text" name="emailDomain" tabindex="1" />
</td>
</tr>

This will then auto-fill the login page with the domain part of the URL entered.

Varnish is a state-of-the-art, high-performance HTTP accelerator, used by sites such as Facebook and Twitter.

You can enable Varnish for your site by following these steps:

1.) Download Varnish from: http://sourceforge.net/projects/varnish/files/

% wget "http://downloads.sourceforge.net/project/varnish/varnish/2.1.2/varnish-2.1.2.tar.gz"

2.) Untar, install:

% tar xvfz varnish-2.1.2.tar.gz
% cd varnish-2.1.2
% ./configure --prefix=/usr/local/varnish/
% make && make install

3.) Open up your /usr/local/varnish/etc/varnish/default.vcl, and set this line block:

 backend default {
.host = "127.0.0.1";
.port = "8080";
}

This will set the hostname and the port where your webserver will stay. This will be the connection details for your webserver. In this case, we will use a local webserver running on port 8080.

4.) Open up your Apache configuration file. Find:

Listen 80

5.) Change to your preferred alternate port:

Listen 8080

6.) Restart Apache:

% apachectl restart

7.) Start Varnish:

% /usr/local/varnish/sbin/varnishd -a :80 -b localhost:8080 -T localhost:8090 -s file,/usr/local/varnish/varnish.cache,4G

To explain the settings briefly:

-a :80 defines the port for Varnish to run on.
-b localhost:8080 defines the port and host of the webserver you want to cache
-T localhost:8090 defines the port and host for the Varnish terminal to run in
-s file,/usr/local/varnish/varnish.cache,4G defines the cache file, and the size limit.

Congratulations! You now have Varnish running.

For more information about Varnish Cache, see: http://varnish-cache.org

With Apache, you can use the mod_expires and mod_deflate modules to gain a performance boost.  The mod_expires module provides caching, while the mod_deflate module compresses downloadable items to decrease bandwidth usage.

Before following this guide, make sure that mod_gzip and mod_expires are enabled for your Apache server. Most base installations of Apache 2.2 and higher are likely to have these by default.

Open up your Apache configuration file. Then, download the configuration file from: http://atmail.com/download/expires-config.txt:

% wget http://atmail.com/download/expires-config.txt

Add the contents of this file to the bottom of your Apache configuration file.

You may use a different Document Root for your Atmail installation; in implementations where you are using the webmail client version, this is usually the case. If this is so, you will need to modify the Directory declarations to suit your Apache root. The config file has the following line that you need to change:

< Directory /usr/local/atmail/webmail/>

Change to your Atmail document root. An installation that uses /var/www/html/atmail/webmail would have the following:

< Directory /var/www/html/atmail/webmail/ >
Save changes, and restart Apache.