Email and domain

You can sign up first and connect the domain afterward.

1. Buy a Microsoft 365 Business plan. You get a temporary email like ******@company.onmicrosoft.com.
2. In the admin center, go to Settings → Domains → Add domain and enter your domain.
3. Microsoft gives you a TXT record. Add it at your domain registrar (Cloudflare, Namecheap, etc.) to prove you own the domain, then click Verify.
4. Follow the on-screen setup and let Microsoft add the other DNS records (mostly the MX record, which routes your mail).
5. Go to Users → Active users, select your user, and change their email to ******@yourdomain.com.

If the domain already receives email somewhere else, move that mailbox first. Otherwise you could lose mail when the MX record changes.