Timezone Setup – NTP

Create a symlink to file localtime:

# ln -sf /usr/share/zoneinfo/EST /etc/localtime

#date

[bash]# chkconfig –level 2345 ntpd on
[bash]# /etc/init.d/ntpd restart

[bash]# chkconfig –list ntpd

To see if the service started successfully, you should check the system log file.

[bash]# grep ntpd /var/log/messages

[bash]# ntpq -pn

For correct synchronization, the delay and offset values should be non-zero and the jitter value should be under 100.

Whitelist domains in exim

Login to the server SSH as root. Make a sender whitelist file.

touch /etc/exim_whitelist_senders

Take a backup of the exim conf and open it.

cp -p /etc/exim.conf /etc/exim.conf.BKP
vi /etc/exim.conf

Add the line on top of the file

addresslist whitelist_senders = wildlsearch;/etc/exim_whitelist_senders

Now search for the line
require verify = sender/callout

Comment that line and add the following below that.

!verify = sender/callout=30s,defer_ok,maxwait=60s
!senders = +whitelist_senders

Save conf file.

Add email address to the /etc/exim_whitelist_senders file one by one. Wildcard is also acceptable here, Eg: *@domain.com

Restart exim