Smarthost email sending problems

I have configured Sendinblue as a smarthost on my GCP server as Google blocks port 25. I've managed to send emails using Mailgun in the past until our company switched SMTP providers. Now, our emails do not go out and display the error below when sending an email. LOG: MAIN cwd=/usr/local/cpanel/whostmgr/docroot 4 args: /usr/sbin/exim -v -M 1p0gUY-00049e-Th delivering 1p0gUY-00049e-Th Transport port=25 replaced by host-specific port=587 Connecting to smtp-relay.sendinblue.com.host.name.com [2606:4700:3035::ac43:deaf]:587 ... failed: Network is unreachable I have used