Server replied: 110 Can’t open SMTP stream

Error while sending mails from the Cpanel >> Squirrel Mail
Connection timed out
Server replied: 110 Can’t open SMTP stream.
Solution:
On shell, open this file
# vi /usr/local/cpanel/base/3rdparty/squirrelmail/config/config.php
CHANGE
$ useSendmail = false;
TO
$ useSendmail = true;
Save the file and the error is fixed.