Cloudflare external dns for a domain

I’m using miab for dns and plan to keep it that way for the box. I have a second domain which I need to move to Cloudflare Registrar and DNS. I read the past posts on cloudflare and external dns. Before making any changes hoping to confirm I understand the steps correctly:

  1. download the zone file for second domain from the box admin panel
  2. delete the second domain dns settings in the box admin panel
  3. import/manually enter the second domain’s dns settings into cloudflare
  4. use cloudflare nameservers

Will using the cloudflare nameservers impact miab mail services for the second domain ?