Thinking of changing over to Cyberpanel, from a server where I don’t have a cp on at the moment.

Currently I don’t use any email on my server, but I’ve set postfix to relay mail via AmazonSES, for any mail generated by my websites.

Would I still be able to do this if I was using CyberPanel, I’m thinking I just disable email in Cyberpanel, and configure postfix manually the same as I currently do. Would this be correct?

Yes, you can do that using any normal tutorial online available, however, we don’t have such document available in our blog/docs yet.