Postfix/smtp connect to host:25 connection timed out

Hello, I had setup a vps where I followed the guideline on Perfect server - CentOS 7. Everything seems fine except the postfix where I can see there are some emails could not be delivered with the following errors in the mail log.

I had the firewall in active with the port 25, 587, 993, 995 enabled. I also did the telnet on the port 25, 587, 993, 995 all working fine.

Could this because of my server settings problem? Any suggestion?

 

Can you ping those domains?

 

Just tested. All the domains could not be ping. So what does this mean

 

it seems the error is elsewhere... somewhere it's blocked but I can't tell you where.

Maybe run a routetrace on the domains and see how far it goes.

 

Below are the traceroute results I did. Any help will be appreciated. Thanks.

 

can't really help you, sorry.

 

Well, I can see that the traceroute results show somewhere been blocked while traceroute to gmail has no problem.

Thanks for your time anyway.