If you find this error in your apache error.log you most likely have rebuild your system and broke a few apache modules.

I received the error after rebuilding my system with EasyApache and using APC + Memcache. I compiled memcache and APC myself, so after rebuilding the system via EasyApache it would receive the error: child pid exit signal segmentation fault 11

If that is not your problem, you should rebuild apache without eaccelerator, acp or memcache, because they can cause the problem.

A very comfortable way to manage all of your e-Mail accounts on your server is: ConfigServer Mail Manage (cmm)
http://www.configserver.com/cp/cmm.html

This is an exclusive! and free! add-on product for cPanel/WHM. The product provides you with an interface to the cPanel user accounts email configuration without having to login to their accounts. It is domain based rather than account based and allows you to do all the following from within WHM:

* View, edit and delete email accounts
* View, edit and delete email forwarders
* View, edit and delete email filters
* View and modify email account quotas
* Modify email account passwords

How to install ConfigServer Mail Manager

1. cd /tmp/
2. wget http://www.configserver.com/free/cmm.tgz
3. tar -xzf cmm.tgz
4. cd cmm/
5. sh install.sh

Yesterday I opened my mail client thunderbird and suddenly a message pops up “Sending password did not suceed”. Wow, great!

After doing some research I finally found a solution. And it’s a well known bug:

The reason this happens is because many cPanel installs were done on top of a Linux install that had a POP3 daemon run from xinetd. You will need to change into the /etc/xinetd.d directory from ssh and find the popa3d and popa3ds files. The files look like this:

# default: off
# description: The POP3 service allows remote users to access their mail \
#              using an POP3 client such as Netscape Communicator, mutt, \
#              or fetchmail.
service pop3
{
        disable = no
        socket_type             = stream
        wait                    = no
        user                    = root
        server                  = /usr/sbin/popa3d
}
 
What you need to do is set the 'disable' parameter to 'yes'. It should look like this when you are done:
 
# default: off
# description: The POP3 service allows remote users to access their mail \
#              using an POP3 client such as Netscape Communicator, mutt, \
#              or fetchmail.
service pop3
{
        disable = yes
        socket_type             = stream
        wait                    = no
        user                    = root
        server                  = /usr/sbin/popa3d
}

Repeat the same for popa3ds and then run:

service xinetd stop
service cpanel restart
service xinetd start

Source

After that simply restart “POP3 service” via WHM/Cpanel and you’ll be fine again.
Annoying, but now it’s fixed!

The following commands are very useful to make sure that imap is running properly:

/scripts/restartsrv_courier
Simple restart of courier.

/scripts/convert2maildir
This will convert your mail boxes into a proper format.

/scripts/courierup –force
This will make sure that the latest imap is running.

If you are on a WHM/Cpanel server and you might want to update your cpanel including all components like FTP, Courier, etc., then you can run the following command via SSH:

/scripts/upcp --force

This will not only make sure you have got the latest Cpanel software, but will also “auto-heal” your system, which means that it will fix some server settings.