powermta skipped connecting to . . . no compatible source IP configured

Question

I have a problem when I try to send email with pmta, i have all the configurations in right place with the right format, but i keep getting this error in the log file, im using centos-6

skipped connecting to . . . no compatible source IP configured

Log File Output:

2019-05-01 12:56:20 PowerMTA(TM) v4.0r8 (2012-09-10 17:27:12, 64-bit; tags/v4_0r8@14145) starting

2019-05-01 12:56:20 Copyright(c) 1999-2012, Port25 Solutions, Inc.  All Rights Reserved.

2019-05-01 12:56:20 Current time: Wed, 1 May 2019 12:56:20 +0000

2019-05-01 12:56:20 Host names: mail.domain.com [127.0.0.1] [10.172.0.5] [IPv6:::1] [IPv6:fe80::4001:aff:feac:5] localhost.domain.com localhost

2019-05-01 12:56:20 Domain suffix: domain.com

2019-05-01 12:56:20 Name servers: 8.8.8.8 8.8.4.4

2019-05-01 12:56:20 SMTP source IP addresses:

2019-05-01 12:56:20     virtual MTA "{default}": (any local)

2019-05-01 12:56:20     virtual MTA "10.172.0.5": 10.172.0.5

2019-05-01 12:56:20 Domain Keys:

2019-05-01 12:56:20 OS: Linux 2.6.32-754.12.1.el6.x86_64 (CentOS release 6.10 (Final))

2019-05-01 12:56:20 glibc v2.12 (stable), NPTL 2.12

2019-05-01 12:56:20 OpenSSL 1.0.0i 19 Apr 2012

2019-05-01 12:56:20 1/1 CPU (x86_64; Intel Xeon CPU @ 2.00GHz)

2019-05-01 12:56:20 1792 MB memory detected

2019-05-01 12:56:20 Priority nice range: min. 15, max. 0

2019-05-01 12:56:20 Use of realtime priorities disabled

2019-05-01 12:56:20 Max. opened files: 32768, max. threads: infinite

2019-05-01 12:56:20 Max. virtual memory: unlimited, max. data size: unlimited

2019-05-01 12:56:20 Using license key ...........

2019-05-01 12:56:20 Spool initialization starting

2019-05-01 12:56:20 Spool /var/spool/pmta

2019-05-01 12:56:20       0 files, 0 directories, nextDir=0

2019-05-01 12:56:20 Total of 0 files in use

2019-05-01 12:56:20 Maximum number of recipients (based on system resources): 1344000

2019-05-01 12:56:20 Running under user pmta (uid 497); group pmta (gid 497)

2019-05-01 12:56:20 Resolver: multi, 4 dispatchers

2019-05-01 12:56:20 SMTP Listener at 0.0.0.0:2025 starting

2019-05-01 12:56:20 Using license key ...........

2019-05-01 12:56:20 Spool initialization complete.

2019-05-01 12:57:20 Queue size: 0 rcpts, 0 domains, 0 queues, 0.0 KB; 0/0 files, 0 dirs

2019-05-01 12:58:20 Queue size: 0 rcpts, 0 domains, 0 queues, 0.0 KB; 0/0 files, 0 dirs

2019-05-01 12:58:20 Moved /etc/pmta/bounces/b-2019-05-01-0000.csv to /etc/pmta/bounces/archived/b-2019-05-01-0000.csv

2019-05-01 12:58:20 Moved /etc/pmta/delivered/d-2019-05-01-0000.csv to /etc/pmta/delivered/archived/d-2019-05-01-0000.csv

2019-05-01 12:59:03 (out 58)starting gmail.com/10.172.0.5

2019-05-01 12:59:03 (out 58)skipped connecting to gmail-smtp-in.l.google.com (2a00:1450:4013:c07::1a): no compatible source IP configured

2019-05-01 12:59:03 (out 58)connecting from domain.com (10.172.0.5) to gmail-smtp-in.l.google.com (108.177.127.26)

2019-05-01 12:59:20 Queue size: 1 rcpt, 1 domain, 1 queue, 0.3 KB; 1/1 file, 1 dir

2019-05-01 13:00:06 (out 58)Timed out, status = ETIMEDOUT

2019-05-01 13:00:06 (out 58)skipped connecting to alt1.gmail-smtp-in.l.google.com (2404:6800:4003:c01::1a): no compatible source IP configured

2019-05-01 13:00:06 (out 58)connecting from domain.com (10.172.0.5) to alt1.gmail-smtp-in.l.google.com (74.125.130.26)

2019-05-01 13:00:20 Queue size: 1 rcpt, 1 domain, 1 queue, 0.3 KB; 1/1 file, 1 dir

2019-05-01 13:00:20 Moved /etc/pmta/bounces/b-2019-05-01-0001.csv to /etc/pmta/bounces/archived/b-2019-05-01-0001.csv

2019-05-01 13:00:20 Moved /etc/pmta/delivered/d-2019-05-01-0001.csv to /etc/pmta/delivered/archived/d-2019-05-01-0001.csv

Can anyone help with this?