How to Create Trusted Outgoing Webhooks

Is there a way to have a trusted outgoing webhook? I have a webhook that is going to an https url that has a RapidSSL certificate (not self-signed), but the error log keeps telling me:

[EROR] Event POST failed, err=Post address forbidden

is there something i need to do on the mattermost server to allow this cert to be trusted?

To be more specific. The integration server and the mattermost server are on the same network. However, both are exposed to the internet. Whitelisting the integration server with “AllowedUntrustedInternalConnections” solves this issue; however, that seems silly and there should be a better solution.

Mattermost blocks access to insecure addresses by default. You should be able to disable this behaviour by setting the EnableInsecureOutgoingConnections config flag to true. If your server is exposed to the wider internet though, whitelisting the specific addresses that you need to be able to access is likely the better option. You can see the details of our HTTP implementation here.