CentOS 7 with MailScanner failed to use Sophos SAVI

CentOS 7 with MailScanner failed to use Sophos SAVI.

My MailScanner doesn't work with SAVI mode (use less CPU resource), just work with Sophos mode (user more CPU resource).

I have complied the SAVI-Perl-0.30 and the after "make" the SAVI.so has been deployed to /usr/local/lib64/perl5/auto/SAVI/SAVI.so.

I set "Virus Scanners = sophossavi" in MailScanner.conf, let it make use SAVI module.
However I got the following error in maillog, keep saying "SAVI Perl module not found"

Apr 20 15:07:56 myserver MailScanner[5266]: MailScanner E-Mail Virus Scanner version 4.85.2 starting...
Apr 20 15:07:56 myserver MailScanner[5266]: Reading configuration file /etc/MailScanner/MailScanner.conf
Apr 20 15:07:56 myserver MailScanner[5266]: Reading configuration file /etc/MailScanner/conf.d/README
Apr 20 15:07:56 myserver MailScanner[5266]: Using SpamAssassin results cache
Apr 20 15:07:56 myserver MailScanner[5266]: Connected to SpamAssassin cache database
Apr 20 15:07:56 myserver MailScanner[5266]: Enabling SpamAssassin auto-whitelist functionality...
Apr 20 15:07:58 myserver MailScanner[5266]: SAVI Perl module not found, did you install it?

If I set  "Virus Scanners = sophos" in MailScanner.conf, it works, but use a lot of CPU and performance is not good.

In the MailScanner.conf, seems no conf to tell the MailScanner where is the SAVI.so file.

Software:
CentOS 7.3 x64
sendmail 8.14 (build-in)
MailScanner 4.85.2
Sophos Antivirus for Linux 9.12.3
SAVI-Perl-0.30

Sophos related settings in MailScanner.conf
Virus Scanners = sophossavi
Sophos IDE Dir = /opt/sophos-av/lib/sav
Sophos Lib Dir = /opt/sophos-av/lib64
Monitors For Sophos Updates = /opt/sophos-av/lib/sav/*.ide

Solution:
It is because the service startup script don't have library path.

Edit /etc/sysconfig/MailScanner and add the following line will fix the issue.
export LD_LIBRARY_PATH=/opt/sophos-av/lib64