I struggle with not have F2F time with students, and I want to avoid email overload as a substitute. Zoom video conferences as "office hours" works, but I like to have the flexibility to be available as needed rather than setting up a specific time. I have found that creating a Slack channel for my courses is a great solution. It allows me to interact with students in real time in a way that emails do not, and it fosters interaction among students as well through the "general" channel. If you haven't used Slack for this purpose, or maybe do not know how it works, I suggest looking into it. Check it out here - https://slack.com/