PowerMTA Server Not starting

I have recently installed PowerMTA server on CentOS 6, every prerequisite was installed according to Document and License was entered in correctly configuration file was also correctly setup in /etc/pmta/config but unable to start pmta service and getting this error in logs,

2015-08-30 16:08:28 Domain suffix: pmta.com
2015-08-30 16:08:28 Name servers: x.x.x.x  x.x.x.x 
2015-08-30 16:08:28 SMTP source IP addresses:
2015-08-30 16:08:28     virtual MTA "{default}": (any local)
2015-08-30 16:08:28 Domain Keys:
2015-08-30 16:08:28 OS: Linux 2.6.32-573.3.1.el6.x86_64 (CentOS release 6.7(Final))
2015-08-30 16:08:28 glibc v2.12 (stable), NPTL 2.12
2015-08-30 16:08:28 OpenSSL 1.0.0d 8 Feb 2011
2015-08-30 16:08:28 8/8 CPUs (x86_64; Intel Xeon CPU X3440 @ 2.53GHz)
2015-08-30 16:08:28 16128 MB memory detected
2015-08-30 16:08:28 Priority nice range: min. 15, max. 0
2015-08-30 16:08:28 Use of realtime priorities disabled
2015-08-30 16:08:28 Max. opened files: 4096, max. threads: infinite
2015-08-30 16:08:28 Max. virtual memory: unlimited, max. data size: unlimited
2015-08-30 16:08:28 Startup error: Invalid LAK signature`

Answer

You have an invalid license file; this can be as simple as a copy & paste error or an actually invalid key. Email [e-mail] to get a new license.