Instead of hosting your own mail server, use a service like SimpleLogin. It allows you to configure custom domains on the paid plan and it simply redirect any email sent to an email alias to your actual inbox. So you never share your actual email address. Secondly, if tomorrow you change email providers, all you have to do is change the destination behind those aliases for the custom domains. It also does catch-all aliases so you can make them up on the fly.
Instead of hosting your own mail server, use a service like SimpleLogin. It allows you to configure custom domains on the paid plan and it simply redirect any email sent to an email alias to your actual inbox. So you never share your actual email address. Secondly, if tomorrow you change email providers, all you have to do is change the destination behind those aliases for the custom domains. It also does catch-all aliases so you can make them up on the fly.