七、企业人员太多，邮箱帐号记不住？让全局邮件列表来帮你，在webmail写邮件时不需要记住对方的邮箱帐号，直接选中即可。
实现方法： #cd $/extmail/tools
#vim makeglobabook.pl
#!/usr/bin/perl -w
#
# makeglobabook.pl
# make extmail globa book for mysql server.
# ver 0.2
use strict;
use DBI;
use IO::File;
use lib "../libs";
use Ext;
use POSIX qw(strftime);
use vars qw(@ISA $usercfg $sysconfig);
my $gbook="../globabook.cf";
my $time = strftime ("%Y\-%m\-%d\_%H\:%M\:%S", localtime);
my $app = Ext->new( config => '../webmail.cf' );
system("mv $gbook $gbook.$time") if -f $gbook;
my $dbuser = $Ext::Cfg{SYS_MYSQL_USER};
my $dbpassword = $Ext::Cfg{SYS_MYSQL_PASS};
my $dbname = $Ext::Cfg{SYS_MYSQL_DB};
my $dbh = DBI->connect("dbi:mysql:database=$dbname",$dbuser,$dbpassword)
or die "Can not connect DB server!\n";
my $query=qq~SELECT `username`,`name` FROM mailbox ~;
my $sth=$dbh->prepare($query);
$sth->execute();
my $fh=IO::File->new(">$gbook");
print $fh "Name,Mail,Company,Phone\n";
while (my @row=$sth->fetchrow_array()){
print $fh "\"$row[1]\",\"$row[0]\"\n";
}
#chmod 755 makeglobabook.pl
#./makeglobabook.pl 就会更新上一级目录的globabook.cf文件了。可放入crontab中定期执行
八、搭建完以后的性能优化，应对500+用户的环境（extmail论坛牛人发的）
1、修改/usr/lib/courier-imap/etc/pop3d
MAXDAEMONS=512
MAXPERIP=9000
2、修改/etc/authlib/authdaemonrc
daemons=256
3、修改/etc/amavisd.conf
$max_servers = 50;
4、修改/usr/sbin/apachectl
HTTPD='/usr/sbin/httpd.worker'
5、修改/etc/httpd/conf/httpd.conf
<IfModule worker.c>
StartServers 10
MaxClients 1500
ServerLimit 100
MinSpareThreads 25
MaxSpareThreads 75
ThreadsPerChild 25
MaxRequestsPerChild 0
</IfModule>
6、修改/etc/clamd.conf
MaxThreads 50
7、修改/etc/my.cnf
max_connections=2048
8、去除rar打包exe会被ban的问题
编辑/etc/amavisd.conf，把$banned_filename_re = new_RE 这段内容相应的修改下
如果你知道该重启哪些服务，就重启这些服务，不清楚的话重启下系统就好。
9、加强发信人限制策略
编辑/etc/postfix/master.cf，把-o smtpd_client_restrictions=permit_sasl_authenticated,reject这行注释去掉。