Beginning early this week optimum’s servers have been intermittently blocking some emails sent from our email system. If you are experiencing delivery issues when sending to your own optonline address, you must call tech support and request whitelisting of your domain.

Update 4/17/19 – Re-verified our systems are not on any of the internet blacklists, and contacted optimum support to try to get mail unblocked, still waiting for confirmation that they fixed the issue.