CheckTLS WhiteList

Add the following IP addresses and domain names to any network filters and/or domain Whitelists at your site.

IP Addresses:

WWW*//email/testTo: ("TestReceiver") originate from here
www11-do.checktls.com167.71.160.115
 2604:a880:800:c1::1ca:9001
 2001:470:1f10:1d7::2
www12-do.checktls.com142.93.73.156
 2604:a880:800:c1::5d:a001
 2001:470:1f10:1cc::2
www12-azure.checktls.com40.76.159.115
 2603:1030:20e:3::136
 
MAIL*test emails originate from here
mail11-do.checktls.com134.209.47.28
 2604:a880:800:c1::277:e001
mail12-do.checktls.com104.131.118.193
 2604:a880:800:14::13e:a000
 
MAILBOX*support and staff emails originate from here
mailbox1-do.checktls.com104.131.168.30
 2604:a880:800:14::177:c000
 
TS*//email/testFrom: ("TestSender") are sent here
ts11-do.checktls.com165.227.190.238
 2604:a880:800:a1::e95:1001
tsa11-do.checktls.com134.209.169.224
 2604:a880:800:c1::2f1:5001

Domain Names:

CheckTLS.com
*.CheckTLS.com

Adding our IP address range to any network filters makes sure our tests are able to do the testing you request from our site.Our tests are non-invasive, non-intrusive, and non-obtrusive. They require no changes to your or any other system. They cause no extra processing and should not trip any security alarms.

Adding our domain to any Whitelists also makes sure our tests can do the testing you request, and it also makes sure any results we email to you get through to you and don't end up in a junk folder or thrown away.