Error in system filter: failed to open filter log file /var/log/filter.log

[error]Error in system filter: failed to open filter log file “/var/log/filter.log”[/error]

Emails on my server were discarded and exim log was showing following error:


Error in system filter: failed to open filter log file “/var/log/filter.log”: Permission denied (euid=506 egid=559)

This error indicates that either file /var/log/filter.log does not exist or ownership of the file is incorrect.

and so server is unable to open the file.


if file is not created then create it and assign following ownership.


touch /var/log/filter.log

chown cpaneleximfilter.cpaneleximfilter /var/log/filter.log

this should fix the issue now.

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iptables error: restorecon command not found

Saving iptables rules:

iptables: Saving firewall rules to /etc/sysconfig/iptables:
/etc/init.d/iptables: line 268: restorecon: command not found [FAILED]

This error mainly occurs due to misisng restorecon file.

restorecon is provided by policycoreutils package. You can try uninstalling and
re-installing policycoreutils package and see if you get restorecon file under /sbin

Installing policycoreutils package:

root@server [~]# yum install policycoreutils

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ip_conntrack: table full,dropping packet

[error]ip_conntrack: table full, dropping packet[/error]

ip_conntrack is an iptables module which limits number of simultaneous connections your system can have.

If this connections are exceed, then your server may not respond to  ping and ssh.

by default a linux Cent OS server have 65536 connection.


Today I faced same issue with my server.  and Fixed for the same was increasing the limit.


You can refer to following tutorials:

Check current limit:

# sysctl net.ipv4.netfilter.ip_conntrack_max

Increase this limit to e.g. 75536, type

sysctl -w net.ipv4.netfilter.ip_conntrack_max=75536

To check current open session, execute following command.

wc -l /proc/net/ip_conntrack

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install memcache/Memcached on centos

Free & open source, high-performance, distributed memory object caching system

Memcached is an in-memory key-value store for small chunks of arbitrary data (strings, objects) from results of database calls, API calls, or page rendering.

Installing Memcached using YUM

If you are using Centos or RHEL, you need to install the RPMforge rpm to install the packs. Go to and download/install the correct rpm/arch belongs to your server.


 yum install memcached

yum install libmemcache


Installing Memcached from source


cd ~/memcache
tar zxvf memcached-1.4.5.tar.gz
cd memcached-1.4.5
./configure --with-lib-event=/usr/local/
make install

Installing libmemecached

cd ~/memcache
tar zxvf libevent-1.4.14b-stable.tar.gz
cd libevent-1.4.14b-stable
make install

Staring the memcached as daemon process


It is advisable to run/start the memcached process as non-root user, you can use the nobody user/group to start.

memcached -d -u nobody -m 1048 -p 11211


Install the Memcache PECL Extension for PHP


Even though memcached is happily running on the server, it’s not accessible from PHP without the PECL extension. Fortunately this is a very easy process, just use the pecl command.


pecl install memcache

Then add the memcache extension to your global php.ini file.


Now restart web server.

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Sorry, no mailbox here by that name. (#5.1.1)

[error]Sorry, no mailbox here by that name. (#5.1.1)[/error]

Try Following Fix.

Error occurs when you send mail to your Parallels Plesk Panel server,

1) make sure that the mail address to which you are trying to send mail really exists and that the “Mail” service for the domain is enabled.

2) Make sure that the domain to which you sent mail is not listed in the “/var/qmail/control/locals” configuration file. The file must contain the entry, “localhost” only .

3) If DrWeb is installed on the server and has no valid license, make sure that LicenseLimit is set to “pass” in /etc/drweb/drweb_qmail.conf

grep License /etc/drweb/drweb_qmail.conf
LicenseLimit = pass

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